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Method development for the certification of a ginsenoside calibration solution via liquid chromatography with absorbance and mass spectrometric detection

September 6, 2018

Author(s)

Walter B. Wilson, Lane C. Sander

The research presented here describes the development of two analytical methods for use in the certification of a ginsenoside calibration solution Standard Reference Material (SRM) 3389 consisting of seven ginsenosides: Rg1, Re, Rf, Rb1, Rc, Rb2, and Rd

Concurrent polarization IR analysis to determine the 3D angles and the order parameter for molecular orientation imaging

September 5, 2018

Author(s)

Young J. Lee

A non-tomographic approach based on polarization-dependent infrared (IR) spectroscopy is proposed for a simultaneous measurement of the 3D angles and the orientational order parameter of a molecular orientation distribution. Unlike conventional

Comparing Aerosol Refractive Indices Retrieved from Full Distribution and Size- and Mass- Selected Measurements

September 1, 2018

Author(s)

James G. Radney, Christopher D. Zangmeister

Refractive index retrievals (also termed inverse Mie methods or optical closure) have seen considerable use as a method to extract the refractive index of aerosol particles from measured optical properties. Retrievals of an aerosol refractive index use two

Evaluation of silicon wafer-based internal reflection elements for use with in situ FT-IR spectroscopy

September 1, 2018

Author(s)

Brent A. Sperling, Berc Kalanyan

Silicon wafer-based internal reflection elements (IREs) present many practical advantages over the prisms conventionally used for attenuated total reflection spectroscopy in the infrared. We examine two methods of using minimally prepared IREs that have

PRIMARY STANDARDIZATION OF THE MASSIC ACTIVITY OF A PROTACTINIUM-233 SOLUTION

August 23, 2018

Author(s)

Ryan P. Fitzgerald, Leticia S. Pibida

Protactinium-233 (233Pa) is used as a tracer for radiochemical analysis and is of particular interest as an isotope dilution mass spectrometry (IDMS) spike for 231Pa/235U radio- chronometry. To this end, we present massic activity determinations by two

Single Cell Viability Measured by Scanning Electrochemical Microscopy and Live/Dead Staining*

August 12, 2018

Author(s)

Kavita M. Jeerage, Tammy L. Oreskovic, Nikki S. Rentz, Damian S. Lauria

Based on its standard reduction potential, ferriciniummethanol can act as an alternate electron acceptor to oxygen during cellular metabolism. By locally oxidizing ferrocenemethanol at a platinum microelectrode, we probed the activity of individual human

Global metabolomic responses in urine from Atm deficient mice in response to LD50/30 gamma irradiation doses

August 9, 2018

Author(s)

Evagelia C. Laiakis, Tytus Mak, Steven J. Strawn, Yi-Wen Wang, Bo-Hyun Moon, Pelagie Ake, Albert J. Fornace

Exposures to ionizing radiation (IR) may either be accidental or intentional, for medical purposes or even through terrorist actions. As certain populations emerge to be more radiosensitive than others, it is imperative to assess those individuals and

Nanoscale partitioning of Paclitaxel in Hybrid Lipid-Polymer Membranes

August 6, 2018

Author(s)

Mohit Tuteja, Minjee Kang, Cecilia Leal, Andrea Centrone

Paclitaxel is a powerful drug against restenosis and many forms of cancer. However, its clinical application hinges on the ability to achieve suitable stabilized drug concentrations in an aqueous suspension while hindering drug crystallization. To engineer

A novel approach to converting alkylated arsenic to arsenic acid for accurate ICP-OES determination of total arsenic in candidate speciation standards

August 3, 2018

Author(s)

Savelas A. Rabb, Lee L. Yu, My D. Le

The National Institute of Standards and Technology has developed a new series of organic As reference materials, SRMs 3030, 3031, 3033 and 3034, for monomethylarsonic acid, dimethylarsinic acid, arsenobetaine and arsenocholine, respectively. These SRMs

Challenges in Developing Analytically Validated Laboratory Derived Dietary Supplement Databases

August 3, 2018

Author(s)

J. M. Betz, Kate Rimmer, Leila Saldanha, Melissa M. Phillips, Karen Andrews, Stephen A. Wise, Laura J. Wood, Adam J. Kuszak, Pavel A. Gusev, Pamela R. Pehrsson

A new realization of SI for organic chemical measurement: NIST PS1 Primary Standard for quantitative NMR (Benzoic Acid)

July 30, 2018

Author(s)

Michael A. Nelson, Jason F. Waters, Blaza Toman, Brian E. Lang, Alexander R?ck, Kathrin Breitruck, Markus Obkircher, Anthony Windust, Katrice A. Lippa

Metrological traceability to common references supports the comparability of chemical measurement results produced by different analysts, at various times, and at separate places. Ideally, these references are realizations of base units of the

Classification of samples from NMR-based metabolomics using principal components analysis and partial least squares with uncertainty estimation

July 25, 2018

Author(s)

Werickson Fortunato de Carvalho Rocha, David Sheen, Dan Bearden

Recent progress in metabolomics has been aided by the development of analysis techniques such as gas and liquid chromatography coupled with mass spectrometry (GC-MS and LC-MS) and nuclear magnetic resonance (NMR) spectroscopy. The vast quantities of data

Determination of polypeptide conformation in water with nanoscale resolution in water

July 24, 2018

Author(s)

Georg Ramer, Francesco Ruggeri, Aviad Levin, Toumas Knowles, Andrea Centrone

The conformational structure and folding of proteins are central to many biological processes. However, misfolding of proteins and peptides can lead to toxic aggregates that are involved in Alzheimers and other neurodegenerative disorders. Methods to