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XiaoJuan Feng, Jintao Zhang, Michael R. Moldover, Inseok Yang, Mark Plimmer, H. Lin
This article describes the accurate determination of the molar mass of a sample of argon gas used for a determination of the Boltzmann constant. The method due to one of the authors [Moldover et al., J. Res. Natl. Bur. Stand. 93, 85-144 (1988)] uses the
Sharlyn Mazur, Elyssia S. Gallagher, Subrata Debnath, Stewart R. Durell, Kyle Anderson, Lisa M. Jenkins, Ettore Appella, Jeffrey W. Hudgens
PPM serine/threonine protein phosphatases function in signaling pathways and require millimolar concentrations of Mn2+ or Mg2+ ions for activity. Whereas the crystal structure of human PP2Cα displayed two tightly bound Mn2+ ions in the active site, recent
Thomas P. Forbes, Edward R. Sisco, Matthew E. Staymates, John G. Gillen
An ambient mass spectrometry (AMS) platform coupling Joule heating thermal desorption (JHTD) and direct analysis in real time (DART) was developed, generating discretely pulsed rapid heating ramps and elevated temperatures for the detection of inorganic
In this paper we examine the two-dimensional tunneling formalism used previously to fit the hydrogen-transfer and internal-rotation splittings in the microwave spectrum of 2 methylmalonaldehyde in an effort to determine the origin of various
Rian You, James Radney, Christopher D. Zangmeister, Michael R. Zachariah
Particles from smoldering biomass burning (BB) represent a major source of carbonaceous aerosol in the terrestrial atmosphere. In this study, mass specific absorption spectra of laboratory- generated smoldering wood particles (SWP) from 3 hardwood and 3
The effective attenuation length (EAL) is normally used in place of the inelastic mean free path (IMFP) to account for elastic-scattering effects when describing the attenuation of Auger electrons and photoelectrons from a planar substrate by an overlayer
Evgheni Strelcov, Qingfeng Dong, Tao Li, Jungseok Chae, Yuchuan Shao, Yehao Deng, Alexei Gruveman, Jinsong Huang, Andrea Centrone
Ferrolectricity has been proposed as a plausible meachanism to explain the high photovoltaic conversion efficiency in organic-inorganic perovskites; however, convincing experimental evidence in support to this hypothesis is still missing. Identifying and
Anthony P. Kotula, Chad R. Snyder, Kalman D. Migler
The Raman spectra of polycaprolactones have been measured over a temperature range of 20 °C to 160 °C to distinguish ordered chain conformers in the melt state and determine the quantitative crystalline bands. Principal component analysis of the spectra in
Meghan C. Burke, Yuri A. Mirokhin, Dmitrii V. Tchekhovskoi, Sanford P. Markey, Stephen E. Stein, Jenny Heidbrink Thompson, Christopher Larkin
We present a mass spectral library based method to identify tandem mass spectra of peptides that contain unanticipated modifications and amino acid variants. We describe this as a hybrid method since it combines matching both ion m/z and mass losses. The
William E. Wallace, Weihua Ji, Dmitrii V. Tchekhovskoi, Karen W. Phinney, Stephen E. Stein
A method to discover and correct errors in mass spectral libraries is described. Comparing across a set of highly curated reference libraries compounds that have the same chemical structure quickly identifies entries that are outliers. In cases where three
John L. Molloy, Swarna Lakshmi, Tin L. Wong, Heather Neu, Sarah Michel, Eric A. Toth
3-hydroxyanthranilate 3,4-dioxygenase (3HAO) is an enzyme in the microglial branch of the kynurenine pathway of tryptophan degradation. 3HAO is a non-heme iron-containing, ring-cleaving extradiol dioxygenase that catalyzes addition of both atoms of O2 to
Edward R. Sisco, Marcela N. Najarro, Daniel V. Samarov, Jeffrey A. Lawrence
This work investigates the stability of trace deposits of six explosives (ETN, PETN, RDX, HMX, TNT, and Tetryl) to determine environmental stabilities and lifetimes. Explosives were inkjet printed directly onto PTFE coated fiberglass substrates and exposed
Moving-window (MW) approaches to two-dimensional correlation spectroscopy (2D-COS) make it possible to characterize spectral changes occurring in a narrow range of perturbation variable (e.g., time, temperature, and concentration). Despite the wide range
Cedric J. Powell, Giorgia Olivieri, Krista Parry, D. J. Tobias, Matthew Brown
Ion spatial distributions at the water-air/vacuum interface are accessible by energy-dependent X-ray photoelectron spectroscopy (XPS). Here we quantify the difference between a flat surface and a cylindrical shaped microjet on the energy-dependent
Georg Ramer, Florian Reisenbauer, Benedikt Steindl, Wolfgang Tomischko, Bernhard Lendl
Photothermal induced resonance (PTIR) is a method for optical spectroscopy that allows for infrared chemical imaging at spatial resolution below the limit of diffraction. By using the mechanical resonance of the cantilever for amplification the technique
Quantitative microanalysis by energy dispersive spectrometry (EDS) of materials with titanium to vanadium ratios ranging from 1:1 to greater than 30:1 is demonstrated to be effective using multiple linear least squares fitting with NIST DTSA II despite a
Column selection is probably the single most important aspect of method development that will directly affect measurement accuracy and precision of liquid chromatographic (LC) measurements. An understanding of physical and chemical properties of LC columns
The development of fit-for-purpose analytical methods is an essential component of chemical metrology. This presentation will provide guidance on approaches for establishing robust analytical methods, particularly with applications to liquid chromatography
Solid Phase Extraction [video, running time 29 minutes 2 seconds] \\europa\839.02\training\Solid Phase Extraction (29.02 minutes).mp4 Lane C. Sander Chemical Sciences Division Material Measurement Laboratory National Institute of Standards and Technology
John Bowden, Jeremy P. Koelmel, Nicholas M. Kroeger, Emily L. Gill, Candice Z. Ulmer, Rainey E. Patterson, Richard A. Yost, Timothy J. Garrett
Untargeted omics analyses aim to comprehensively characterize biomolecules within a biological system. Changes in the presence or quantity of these biomolecules can indicate important biological perturbations, such as those caused by disease. With current
Joshua R. Biller, Karl F. Stupic, Anthony B. Kos, Timothy Weilert, George Rinard, Yoshi Nakashima, John M. Moreland
A low-field nuclear magnetic resonance (NMR) instrument is an important tool for investigating a wide variety of samples under different conditions. In this paper, we describe a system constructed primarily with commercially available hardware and control
Ariel H. Hecht, Jeff E. Glasgow, Paul Jaschke, Lukmaan Bawazer, Matthew S. Munson, Jennifer R. Cochran, Drew Endy, Marc L. Salit
Our understanding of translation represents a cornerstone of molecular biology and underpins our capacity to engineer living matter. For decades, the codon AUG and a few near-cognates (GUG, UUG) have been exclusively considered as start codons for
Marlon L. Walker, David J. Vanderah, Kenneth A. Rubinson
In-situ spectroscopic ellipsometry was used to examine the adsorption of self-assembled monolayers (SAMs) of HS(CH2)3O(CH2CH2O)5CH3 C3(EO)5}, HS(CH2CH2O)6CH3 (EO)6}, and [S(CH2CH2O)6CH3]2 [S(EO)6]2} from aqueous solution onto Au substrates. The adsorption