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The Quarterly Magazine of NIST’s Material Measurement Laboratory

SPRING 2017

MATERIAL MATTERS

MEASUREMENT SCIENCE FOR 

INFRASTRUCTURE RENEWAL
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TABLE OF CONTENTS

A Message from the MML Director 3

Move Over, Superman! NIST ‘Spectral Fingerprinting’ Sees Through Concrete to Detect Early Corrosion 4

Silk Sensor Could Speed Development of New Infrastructure, Aerospace and Consumer Materials 5

NIST Quest for Climate-Friendly Refrigerants Finds Complicated Choices 6

Precipitation Kinetics and Development Pathway of the Most Widely Used Aircraft Alloy 7

Better Nanoimages ‘Spin’ the Path to Improved Magnetic Memory 8

NIST Patents First DNA Method to Authenticate Mouse Cell Lines 9

Graphene Lid Revitalizes Imaging Technique 10

‘Start Codons’ in DNA and RNA May Be More Numerous Than Previously Thought 12

NIST Technology Used to Help Identify Key Enzymes in Disease 13

Popular Proteomics Tool Now Incorporates NIST Mass Spectral Search Software 13

Outreach and Partnering 14

Awards 16

MML Measures Up: Improving Pipeline Materials 18

Publications 19

Cover Image: Rust on Iron. Credit: Laitr Keiows, Creative Commons license 3.0

CONTRIBUTORS

Editor | Torey Liepa

Contributors | Alison Gillespie | Leah Kauffman | Michael Newman | Laura Ost | Ben Stein 

Contact MML | mmlinfo@nist.gov
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A MESSAGE FROM THE MML DIRECTOR

According to the American Society of Civil Engineers, nearly ten percent America’s bridges 

are structurally deficient or functionally obsolete, one-fifth of our highway pavement is in 

poor condition, and over two trillion gallons of treated drinking water is wasted each year 

from an estimated 240,000 water main breaks. In short, our nation’s physical infrastructure 

is in bad shape, and in dire need of attention. 

A healthy physical infrastructure is essential for maintaining our physical security, preserving 

our quality of life, and helping our economy thrive. At NIST’s Material Measurement Lab 

(MML), we are working to make a safe and healthy infrastructure a reality. From providing 

quality assurance standards that cement and steel manufacturers can rely upon to providing 

accurate assessment tools for pipeline manufacturers and water treatment, our work enables 

a better, more reliable infrastructure network.

With so much of our infrastructure in need of attention, MML research also gives decisionmakers the intelligence they need to prioritize our nation’s many infrastructure projects. 

Our work helps ensure the accuracy of steel hardness measurements, which are used to 

check the strength of steel alloys that may be used in infrastructure projects. We measure 

impact energy, which helps to predict when structures are in need of replacement or repair 

(before catastrophic failure). We also calibrate the equipment that can measure flaws and 

weaknesses in existing infrastructure without damaging it or taking it out of service.

To ensure we continue to innovate and lead physical infrastructure measurement, we have 

renewed our dedication to infrastructure research by making it part of the MML Strategic 

Plan. Our plan directs our materials and chemical scientists and engineers to develop new 

materials models that fully account for the ongoing reduction in structural capacity in 

infrastructure components and systems. Such models promise to guide the development of 

new infrastructure materials resulting in more effective, lower cost solutions. 

In this issue of Material Matters, you can read about some of our latest infrastructure 

research, including advanced corrosion detection (p. 4), an embedded, nanoscale composite 

damage sensor (p. 5), and our ongoing project to improve pipeline materials (p. 18), in 

addition to research across the other areas of MML’s research portfolio.

Part of NIST’s mission is to improve quality of life, and little is more central to the quality 

of our lives than the infrastructure in which we live. Though much needs to be done, at 

MML we have the right tools to put words into action.

*During the transition to a new presidential administration, Laurie Locascio, MML director, is 

serving as NIST’s acting associate director for laboratory programs. Michael Fasolka, long-time 

MML deputy director, is acting director of MML

Michael Fasolka, Ph.D.

Director*

Material Measurement 

Laboratory

NIST
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MOVE OVER, SUPERMAN! NIST ‘SPECTRAL FINGERPRINTING’ SEES THROUGH 

CONCRETE TO DETECT EARLY CORROSION

When you suffer a fall, an on-the-field 

collision or some other traumatic blow, 

the first thing the doctor will do is take 

an X-ray, CT scan or MRI to determine 

if anything has been damaged internally. 

Researchers at NIST are using the 

same principle, but in a more powerful 

form, to detect corrosion, the primary 

danger threatening the health of the 

steel framework within the nation’s 

bridges, roads and other aging physical 

infrastructure.

What they have developed is a 

noninvasive “spectral fingerprint” 

technique that reveals the corrosion 

of concrete-encased steel before it can 

cause any significant degradation of 

the structure it supports. The detection 

method is described in a new paper in the 

journal Applied Magnetic Resonance. 

When water and oxygen corrode 

iron, different iron oxide products are 

produced, with the two most common 

being goethite and hematite. “The 

brown rust that forms when you leave 

a hammer out in the rain is mostly 

goethite, and when a steel reinforcing 

bar [rebar] corrodes inside a concrete 

bridge deck, that is mostly hematite,” 

said NIST physical chemist Dave

Plusquellic. “We have shown in our new 

study with goethite, and our previous

work with hematite, that terahertz 

radiation—electromagnetic waves with 

frequencies 10 to 100 times higher than 

the microwaves used to cook food—can 

detect both corrosion products in the 

early stages of formation.”

Current imaging methods for 

uncovering corrosion use microwaves 

to record changes in the physical state 

of the affected steel, such as changes 

in the thickness of a rebar within the 

concrete of a bridge or other structure. 

“Unfortunately, by the time such changes 

are detectable, the corrosive process is 

already well on its way toward causing 

cracks in the concrete,” said physicist and 

NIST Fellow Ed Garboczi. 

Additionally, Garboczi said most 

of the microwave imaging methods 

rely on comparisons with baseline 

measurements of the steel taken at the 

time of construction, a practice that 

only goes back about 25 years. “That’s a 

real problem since the average age of the 

400,000 steel-reinforced concrete bridges 

in the United States is 50 years and there 

is no baseline data available for many of 

them,” he explained.

The NIST terahertz wave detection 

method works because goethite and 

hematite are antiferromagnetic. In other 

words, the pairs of electrons sitting sideby-side within the iron atoms in these 

materials spin in opposite directions, 

leaving them unaffected by external 

magnetic fields. In contrast, the electrons 

in the iron atoms of a household magnet, 

which is ferromagnetic, spin in the same 

direction and are either attracted or 

repelled by external magnetic fields.

“Terahertz waves will flip the spin 

alignment of one of the electrons in a 

pair and get absorbed by hematite or 

goethite,” Plusquellic said. “Using a 

millimeter wave detector, we discovered 

that this antiferromagnetic absorption 

only occurs within narrow frequency 

ranges in the terahertz region of the 

electromagnetic spectrum—yielding 

‘spectral fingerprints’ unique to goethite 

and hematite, and in turn, iron 

corrosion.”

With current advances in terahertz 

sources and detectors, the new NIST 

nondestructive evaluation technique has 

the potential to rapidly detect tiny amounts 

of iron-bearing oxides from early-stage 

corrosion of steel surrounded by concrete, 

polymer composites (such as pipe insulation 

in a factory), paints and other protective 

materials.

“In the laboratory, we have demonstrated 

that a 2-milliwatt terahertz source can 

produce waves that detect hematite through 

25 millimeters of concrete,” Plusquellic 

said. “Using terahertz sources with powers 

in the hundreds of milliwatts and stateof-the-art receivers with unprecedented 

signal-to-noise ratios, we should be able 

to penetrate 50 millimeters, the thickness 

of the concrete covering the first layer of 

rebar used in most steel-reinforced concrete 

structures.”

Next up for the NIST team will be an 

attempt to find a spectral fingerprint for 

akageneite, an iron corrosion product 

formed in the presence of chloride ions, 

which come from sources such as seawater 

and road deicing salt. “Akageneite can 

cause problems in steel-reinforced concrete 

similar to those seen with goethite and 

hematite,” Garboczi said.

The antiferromagnetic corrosion detection 

method was first conceived in 2009 by the 

late William Egelhoff, a NIST fellow and 

pioneer in the field of magnetic materials. 

S.G. Chou, P.E. Stutzman, V. Provenzano, R.D. McMichael, 

J. Surek, S. Wang, D.F. Plusquellic and E.J. Garboczi, Using 

Terahertz Waves to Identify the Presence of Goethite via 

Antiferromagnetic Resonance, Applied Magnetic Resonance

(April 2017), http://dx.doi.org/10.1007/s00723-017-0884-y

An abandoned building on Northern California’s McAbee Beach shows the destructive power of corrosion on a steelreinforced concrete structure. A new NIST evaluation method using terahertz waves can detect the early stages of 

corrosion on steel rebars directly through their concrete covering. Credit: Per Loll
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SILK SENSOR COULD SPEED DEVELOPMENT OF NEW INFRASTRUCTURE, AEROSPACE AND 

CONSUMER MATERIALS

Consumers want fuel-efficient vehicles 

and high-performance sporting goods, 

municipalities want weather-resistant 

bridges, and manufacturers want more 

efficient ways to make reliable cars 

and aircraft. What’s needed are new 

lightweight, energy-saving composites 

that won’t crack or break even after 

prolonged exposure to environmental 

or structural stress. To help make that 

possible, researchers working at NIST 

have developed a way to embed a 

nanoscale damage-sensing probe into a 

lightweight composite made of epoxy and 

silk.

The probe, known as a mechanophore, 

could speed up product testing and 

potentially reduce the amount of time 

and materials needed for the development 

of many kinds of new composites.

The NIST team created their probe from 

a dye known as rhodamine spirolactam 

(RS), which changes from a dark state to 

a light state in reaction to an applied

force. In this experiment, the molecule 

was attached to silk fibers contained 

inside an epoxy-based composite. As 

more and more force was applied to the 

composite, the stress and strain activated 

the RS, causing it to fluoresce when 

excited with a laser. Although the change 

was not visible to the naked eye, a red 

laser and a microscope built and designed 

by NIST were used to take photos inside 

the composite, showing even the most 

minute breaks and fissures to its interior, 

and revealing points where the fiber 

had fractured. The results were recently 

published in the journal Advanced Materials 

Interfaces.

The materials used in the design of 

composites are diverse. In nature, 

composites such as crab shell or elephant 

tusk (bone) are made of proteins and 

polysaccharides. In this study, epoxy was 

combined with silk filaments prepared by 

Professor Fritz Vollrath’s group at Oxford 

University using Bombyx mori silk worms. 

Fiber-reinforced polymer composites such 

as the one used in this study combine 

the most beneficial aspects of the main 

components—the strength of the fiber and 

the toughness of the polymer. What all 

composites have in common, though, is 

the presence of an interface where the

Continued on page 11

Examples of the silk used in experiments to detect damage in composites, shown under black light. (Left) Ordinary 

fibroin of the Bombyx mori silk worm. The observed fluorescence is the result of molecules already present in the 

protein structure of the fiber. (Middle) Mechanophore-labeled silk fiber fluoresces in response to damage or stress. 

(Right) Control sample without the mechanophore. Credit: Chelsea Davis and Jeremiah Woodcock/NIST

Activation of the mechanophore at the interface of a single fiber bundle silk epoxy by mechanical deformation. 

Credit: Advanced Materials Interfaces
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NIST QUEST FOR CLIMATE-FRIENDLY REFRIGERANTS FINDS COMPLICATED CHOICES

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Researchers at NIST have just completed 

a multiyear study to identify the 

“best” candidates for future use as air 

conditioning refrigerants that will have 

the lowest impact on the climate.

Unfortunately, all 27 fluids NIST 

identified as the best from a performance 

viewpoint are at least slightly flammable, 

which is not allowed under U.S. safety 

codes for most end uses. Several fluids 

among the list of refrigerants are highly 

flammable, including propane, the fuel 

for outdoor grills.

In other words, the NIST study found 

no ideal refrigerant that combined low 

“global warming potential” (GWP)—a 

measure of how much heat a gas will trap 

if released into the atmosphere— with 

other desirable performance and safety 

features such as being both nonflammable 

and nontoxic. The results appear in 

Nature Communications.

“The takeaway is there is no perfect, easy 

replacement for current refrigerants,” 

NIST chemical engineer Mark McLinden 

said. “Going into the study, we thought 

surely there has to be something else. 

Turns out, not so much. So it was a bit 

surprising, a bit disappointing.”

To help reduce global warming, nearly 

200 nations, including the United States, 

in October 2016 agreed to amend the

Montreal Protocol to phase down by 

mid-century the refrigerants used in most 

air conditioning (AC) systems. The partial 

phase down, rather than a complete 

phaseout, recognized the complicated 

choices that will need to be made to select 

replacements. Fortunately, valuable new 

data are now available to support those 

decisions.

“The path forward will involve tradeoffs,” 

McLinden continued. “Safety codes could 

be revised to allow the use of slightly 

flammable refrigerants. Blends of two or 

more fluids could yield a nonflammable 

refrigerant, but at a higher GWP. Carbon 

dioxide is nonflammable, but would 

require a complete redesign of AC 

equipment.”

Copyright: Carolyn Franks/Shutterstock

Current refrigerants are hydrofluorocarbons (HFCs), which are 

“greenhouse gases” with high GWPs. 

Although their contribution to climate 

change is now small, it is expected to 

rapidly increase along with the use of 

air conditioning around the world. 

The Montreal Protocol, the treaty that 

regulates substances that deplete Earth’s 

protective ozone layer, originally spurred 

the introduction of HFCs as replacements 

for ozone-depleting compounds 

previously used.

U.S. regulators already recognize the 

difficulty of choosing new refrigerants. 

The Environmental Protection Agency 

has not set specific GWP limits, but 

rather has conducted comparative risk 

analyses for each refrigerant and end use. 

The criteria include atmospheric effects 

and related health and environmental 

effects, ecosystem risks, consumer risks, 

flammability, cost and availability.

To help U.S. policymakers and industry 

understand the limits and tradeoffs 

involved in a phase-down of the HFCs, 

NIST undertook a comprehensive, fouryear search for the best single-component, 

low-GWP replacement fluids. GWP is 

defined as the warming potential of one 

kilogram of a gas relative to one kilogram 

of carbon dioxide.

The NIST study focused on possible 

replacement fluids for small AC systems 

typical for homes and small businesses. A 

blend of HFCs called R-410A is now the 

most popular refrigerant in such systems. 

These AC units are sealed, meaning 

they should not release HFCs into the 

atmosphere. However, the systems can leak, 

and when they are serviced or discarded, 

refrigerant may escape and not be recovered 

and recycled, McLinden said.

The study screened a database of more 

than 60 million chemicals, estimating the 

properties based solely on their molecular 

structure. This built upon a computational 

method previously developed at NIST.

Because all current refrigerants are small 

molecules, the NIST search was limited 

to molecules with 18 or fewer atoms and 

only eight elements that form compounds 

volatile enough to serve as refrigerants. This 

initial screen resulted in 184,000 molecules 

to be considered further.

Screening for energy properties 

corresponding to fluids usable in small 

AC systems and GWP of less than 1,000 

(conventionally understood to be the effects 

over a 100-year timespan) yielded 138 

fluids. The researchers then simulated the 

performance of these 138 compounds in air 

conditioners. A co-author at The Catholic 
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University of America in Washington, 

D.C., helped develop the simulation 

model and evaluate the results. Further 

screening to rule out chemically unstable 

or very toxic compounds or those with 

low energy efficiency resulted in the final 

list of 27 low-GWP fluids.

Propane has a GWP of 3, much lower 

than R-410A’s value of 1,924. Potential 

refrigerants with the lowest GWPs 

include ammonia, commonly used in 

large industrial refrigeration systems 

but toxic and slightly flammable, and 

dimethylether, a propellant and potential 

fuel that is only slightly less flammable 

than propane. Carbon dioxide has a 

GWP of 1 and is nonflammable, but 

it would require a different type of 

refrigeration cycle operating at very high 

pressures. Other low-GWP compounds 

include hydrofluoroolefins, a current 

focus of industry research but slightly 

flammable.

Although there is no specific GWP limit 

in the United States, phaseout dates have 

been set for some of the highest-GWP 

HFCs. (Refrigerants with a GWP of less 

than 750 are allowed in the European 

Union for small AC systems.)

NIST’s list may offer new ideas because 

it includes many refrigerants that are 

not yet on the EPA list of acceptable 

substitutes. The refrigeration industry has 

been actively developing new fluids that 

are slightly flammable, and the results 

of the present study support this course, 

McLinden said. Looking forward, the 

NIST study’s conclusions indicate the need 

to recognize and deal with tradeoffs in 

planning for the future, he said.

For example, how should safety codes 

be changed to ensure that flammable 

refrigerants can be used safely? Blends 

of different refrigerants may offer a 

compromise between safety and GWP. For 

example, a low GWP but flammable fluid 

blended with a nonflammable but highGWP fluid could result in a nonflammable 

fluid with a moderate value of GWP, 

McLinden noted.

This work was supported by the U.S. 

Department of Energy.

M.O. McLinden, J.S. Brown, R. Brignoli, A.F. Kazakov and 

P.A. Domanski, Limited options for low-global warmingpotential refrigerants, Nature Communications, 2017, 

http://dx.doi.org/10.1038/ncomms14476

PRECIPITATION KINETICS AND DEVELOPMENT PATHWAY OF THE MOST WIDELY USED AIRCRAFT ALLOY

The U.S. aluminum industry is estimated to have generated more than $75 billion a year in direct economic 

impact in 2016. Aluminum alloy 2024 (AA2024), which makes use of copper as the main alloying element 

and features a good combination of yield strength and toughness, is the most widely used aircraft alloy. Its 

strengthening mechanism is precipitation hardening, achieved through heat treatment. Despite its obvious 

commercial importance, a comprehensive understanding of the in situ evolution of the precipitate structure 

and morphology of AA2024 during heat treatment is still lacking, mostly due to the sub-angstrom to 

micrometer size range that must be characterized.

Under a partner-user agreement 

between NIST and the Advanced 

Photon Source at the Argonne 

National Laboratory, NIST 

researchers have recently developed 

a synchrotron-based scattering 

methodology that enables acrosslength-scale characterization of 

structural and microstructural 

transformation in a wide range of 

engineering and functional materials. 

The researchers employed 

this methodology to examine the 

nucleation and growth of the 

hardening precipitates in AA2024, 

and determine the corresponding kinetic time scales and activation energies. These behaviors are critical to 

understanding the hardening of the alloy, which is achieved by impeding the movement of dislocations with 

precipitates.

An improved understanding of the precipitation kinetics, together with their atomic structure and microstructure, can serve to establish the structure–performance relationships in alloys, and lead to a more 

rational design of alloys for specific applications.

Zhang, F., Levine, L. E., Allen, A. J., Campbell, C. E., Creuziger, A. A., Kazantseva, N., Ilavsky, J., In Situ Structural Characterization of Ageing Kinetics 

in Aluminum Alloy 2024 across Angstrom-to-Micrometer Length Scales, ACTA Materialia 111, 2016, https://doi.org/10.1016/j.actamat.2016.03.058 

(Left) Recently developed synchrotron-based scattering methodology enables angstrommicrometer structural and micro-structural characterization of the same sample volume. (right) 

In situ synchrotron study reveals temperature-dependent growth kinetics of the precipitates in 

industrially important aluminum alloy 2024.

Electron diffraction patterns of 

phases identified in the AA2024 

alloy. Credit: Nataliya Kazantseva
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Strips of magnetic material (small colored rectangles) sit atop blocks of a nonmagnetic heavy metal (large blue 

rectangles). When an electric field is applied to a nonmagnetic block, a flow of spin-polarized electrons enters 

the magnetic strips and alters the direction of magnetization (black arrows). Credit: Dill/NIST

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BETTER NANOIMAGES ‘SPIN’ THE PATH TO IMPROVED MAGNETIC MEMORY

In work that could help make possible 

a faster, longer-lasting and lower-energy 

method of data storage for consumers and 

businesses, researchers at NIST and their 

colleagues have developed a technique for 

imaging and studying a promising class 

of magnetic devices with 10 times more 

detail than optical microscopes.

Magnetic materials have attracted a 

growing number of researchers in the 

quest to more rapidly store and read bits 

of digital information. In a magnetic 

system, data is encoded by the direction 

of the magnetization: A bar magnet with 

its north pole pointing up can represent 

the binary code “0,” while the same 

magnet with its north pole pointing down 

can represent a “1.” Unlike the standard 

semiconductor computer chip, magnetic 

memory devices can retain information 

even if the power is turned off.

By controlling when and how quickly 

the magnetization can be flipped without 

expending significant electrical power, 

scientists hope to improve an existing 

technology called Magnetic Random 

Access Memory, or MRAM, into a 

leading tool for reading, writing and 

storing information. MRAM is not yet 

competitive with other existing methods 

of data storage such as flash RAM, 

but offers advantages over present-day 

technologies such as reduced energy 

consumption.

To realize the promise of MRAM, 

researchers are probing the nanometerscale magnetic structure of thin metal 

films that have the potential to serve as 

memory devices in MRAM. At NIST, 

Ian Gilbert and his colleagues have 

used a high-resolution electron-imaging 

technique, developed by physicist John 

Unguris, to examine the nanostructure 

of magnetic films before and after their 

magnetization is reversed.

Gilbert and his collaborators, which 

include scientists from NIST and the 

University of Maryland, also used 

electron spin to flip the magnetization 

in their thin-film sample, an alloy of 

cobalt, iron and boron. By passing a small 

electric current through an underlying 

strip of a nonmagnetic metal film such 

as platinum, the team created a stream 

of electrons whose spins all point in the 

same direction. When this stream of 

electrons, known as a spin current, passed 

through the magnetic thin film, their spin 

exerted a small twisting force, or torque, 

on the magnetic regions of the film. The 

torque was large enough to rotate and flip 

the magnetization.

The SEMPA images taken before a 

current was applied revealed that the 

direction of the magnetization varied, 

on the nanoscale, across the thin-film 

sample. Each small region of the sample 

has its own preferred axis along which the 

magnetization points, said Gilbert. The 

team recently reported its findings in the 

journal Physical Review B.

Continued on page 11

The technique, scanning electron 

microscopy with polarization analysis 

(SEMPA), uses a beam of electrons 

scattered from a thin film to reveal the 

nanoscale topography, replete with 

miniature hills and valleys, of the film’s 

surface. Electrons ejected from the surface 

by the incoming electron beam are also 

detected and separated according to 

the direction of their spin—a quantum 

property that endows the charged 

particles with an intrinsic angular 

momentum and tiny magnetic field. The 

direction of the ejected electrons’ spins 

reveals variations in the sample’s magnetic 

structure—changes in the direction of 

magnetization—on a scale about 10 

times smaller than seen with an optical 

microscope.

SEMPA’s ability to discern tiny magnetic 

structures is critical as engineers fabricate 

smaller and smaller magnetic memory 

devices, noted Gilbert. With SEMPA, “we 

can see these really fine textures in the 

magnetization,” he said.
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“A case of mistaken identity” may 

drive the plot of the latest spy film 

or crime novel, but it’s only a tale of 

trouble for geneticists, oncologists, 

drug manufacturers and others working 

with mouse cell lines, one of the most 

commonly used laboratory model systems 

for genetic research. Cell lines that have 

been contaminated or misidentified 

due to poor laboratory technique and 

human error lead to inaccurate research 

studies, retracted publications and wasted 

resources. In fact, many scientific funding 

organizations, such as the National 

Institutes of Health, now require scientists 

to verify their cell lines for identity and 

quality before research grants are awarded. 

To help address this challenge, NIST 

is working with partners to design 

tools, establish datasets, and further 

develop and standardize NIST’s system 

to authenticate mouse cell lines. One 

of the first milestones in this effort is 

the recently granted U.S. patent (No. 

9,556,482) for an authentication method 

using NIST-identified short tandem 

repeat (STR) markers─tiny repeating 

segments of DNA found between 

genes─for mouse cell lines. The method 

can be used to verify that a cell line is 

derived from a particular mouse in the 

same way forensic experts can confirm the 

identify of a person using DNA evidence. 

Once upcoming interlaboratory tests of 

the STR markers are completed, this will 

become the world’s first validated method 

for the authentication of mouse cell lines.

The new NIST authentication method 

uses STR markers that are non-coding 

(that is, do not provide instructions 

for protein production the way genes 

do) DNA segments with a specific 

sequence of nucleotide bases─the four 

key components of DNA known as 

adenine, cytosine, guanine and thymine. 

Each STR is considered a separate 

marker for genetic matching because the 

number of times it is repeated is unique 

to an individual within a species. For 

example, a cell line may have one STR 

sequence─such as G-A-T-A─that repeats 

five times, another─say G-T-A-T─six 

times, a third seven times and so on. If 

another cell line has a high percentage 

of the same STR sequences in the same 

numbers, it is considered likely that they 

share a common ancestry. 

Misidentified human cell lines and 

the disruption they cause have been 

documented for decades. For example, 

two tainted cell lines were responsible for 

invalidating approximately $700 million 

of research studies and some 7,000 

publications between the late-1950s and 

mid-1960s. The International Cell Line 

Authentication Committee, a volunteer 

group that monitors and raises awareness 

of authentication issues, currently lists 

nearly 500 misidentified human cell lines 

in its database. Fortunately, there are now 

standards and public databases that labs 

can use to confirm the identity of their 

human cell lines.

In contrast, the extent of misidentification 

in mouse cell lines is unknown and 

there are currently no guidelines 

for authenticating them, said NIST 

microbiologist Jamie Almeida. “That is 

why NIST has been working on STR 

markers that are unique, easy to interpret 

and capable of distinguishing between 

different mouse cell lines,” Almeida 

said. “Additionally, we have partnered 

with the ATCC [formerly the American 

Type Culture Collection], a global leader 

in biological materials management 

and standards, to further develop the 

STR technology for authentication 

and establish the Mouse Cell Line 

Authentication Consortium. The 

consortium is made up of organizations 

that have agreed to work with NIST and 

ATCC to test and validate the patented 

authentication method using the NISTidentified STR markers.”

The consortium also will create a 

consensus standard to unify how 

authentication is performed across 

laboratories and will establish a public 

database that defines which STR profiles 

identify which mouse cell lines.

“In the future, we hope to see the 

NIST-identified mouse STR markers 

and authentication method incorporated 

into a commercially available assay 

kit,” Almeida said. “The proposed kit, 

combined with a consensus standard 

and a cell line database, would provide 

researchers worldwide with the tools 

needed to ensure the identity of their 

mouse cell lines.”

The new mouse cell line authentication 

method using the NIST-identified STR 

markers is available for licensing for 

research and non-exclusive commercial 

purposes through the agency’s Technology 

Partnerships Office.

A fluorescent microscope image of NIH 3T3 fibroblast cells, a commonly used mouse cell line. Microtubules 

within the cell appear green while the nuclei show as red. NIST and partners are developing tools, datasets and a 

standardized authentication method to ensure the identity of mouse cell lines used in research. 

Credit: Jan Schmoranzer/Leibniz-Institut für Molekulare Pharmakologie

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NIST PATENTS FIRST DNA METHOD TO AUTHENTICATE MOUSE CELL LINES
1 0 |

By capping liquids with graphene, an 

ultrathin sheet of pure carbon, researchers 

at NIST and their colleagues have 

revitalized and extended a powerful 

technique to image surfaces. The 

graphene lids enable researchers for the 

first time to easily and inexpensively 

image and analyze liquid interfaces 

and the surface of nanometer-scale 

objects immersed in liquids. The new 

capability has the potential to advance the 

development of batteries, highly charged 

capacitors for power-grid technology, and 

new catalysts such as those used in the 

chemical industry.

In the imaging technique, known as 

photoemission electron microscopy 

(PEEM), ultraviolet light or X-rays 

bombard a sample, stimulating the 

material to release electrons from a region 

at or just beneath its surface. Electric 

fields act as lenses, focusing the emitted 

electrons to create an image.

Researchers have used the method for 

decades to discern such fine-scale features 

as the patterns of chemical reactions 

on the surface of catalysts, as well as 

the magnetic field structure of memory 

devices and the molecular architecture of 

biological compounds. But PEEM has 

typically been restricted to solid surfaces 

that are in a high-vacuum environment. 

The method hasn’t had the ability to 

study liquids and gases at ordinary 

pressures. A liquid sample, for instance, 

would evaporate and create sparks if 

directly exposed to the high vacuum in 

the PEEM setup.

In the past, scientists have attempted 

to overcome these challenges by using a 

technique known as differential pumping, 

which bridges the gap between the high 

pressure of the sample and the essentially 

zero pressure of the microscope. But such 

instrumentation is not sufficient to reach 

truly ambient pressure conditions and is 

too expensive and not widely accessible 

for routine use, notes NIST physicist 

Andrei Kolmakov.

Instead, he and his colleagues from NIST, 

the University of Maryland, the University 

of Saskatchewan, the Canadian Light 

Source and Oregon State University 

developed a cost-effective and easy-toimplement alternative. Sealing a liquid or 

gaseous sample with a graphene lid just 

one or two atomic layers in thickness keeps 

the sample at atmospheric pressure while 

allowing the system to be placed under 

vacuum.

In a recent issue of Nano Letters, the 

scientists reported that the graphene lid 

enabled electrons emitted by the test liquid 

to pass nearly unimpeded to the detector, 

yet kept the liquid from escaping into the 

vacuum of the PEEM. An array of the lids 

retained the liquid samples for hours under 

high vacuum, long enough to perform 

routine electron imaging and spectroscopy 

experiments.

“This very simple solution, adding a layer of 

graphene,” allows researchers to use PEEM 

in its standard configuration without the 

need for extra and expensive equipment, 

said Kolmakov. 

“The concept of extending the use of PEEM 

to probe liquids is in a way revolutionary,” 

commented physicist Andrea Locatelli of 

Synchrotron Radiation Laboratory Elettra 

in Trieste, Italy, who was not part of the 

research team. “Countless applications can 

indeed be foreseen,” he added.

For instance, noted Kolmakov, the lids 

allow the liquid to be changed while 

an experiment is in progress, helping 

researchers to understand the behavior 

of the sample under different chemical 

environments. In addition, because the 

setup uses an array of identical lids, each 

can be a different sample, and the technique 

can be used in conjunction with powerful 

statistical analysis, data mining and pattern 

recognition methods.

H. Guo, E. Strelcov, A. Yulaev, J. Wang, N. Appathurai, S.

Urquhart, J. Vinson, S. Sahu, M. Zwolak, and A. Kolmakov, 

Enabling Photoemission Electron Microscopy in Liquids via 

Graphene-Capped Microchannel Array, Nano Letters, 2017, 

http://dx.doi.org/10.1021/acs.nanolett.6b04460

Experimental set-up shows an array of graphene-capped liquids. The caps enable the liquids to be studied using an 

image technique that previously was restricted to studying solid surfaces. Credit: A. Strelkov/NIST

|

GRAPHENE LID REVITALIZES IMAGING TECHNIQUE
| 11

Continued from page 5

components meet. The resilience of that 

interface is critical to a composite’s ability 

to withstand damage. Interfaces that are 

thin but flexible are often favored by 

designers and manufacturers, but it is 

very challenging to measure the interfacial 

properties in a composite.

“There have long been ways to 

measure the macroscopic properties 

of composites,” said researcher Jeffrey 

Gilman, who led the team doing the 

work at NIST. “But for decades the 

challenge has been to determine what was 

happening inside, at the interface.”

One option is optical imaging. However, 

conventional methods for optical imaging 

are only able to record images at scales 

as small as 200-400 nanometers. Some 

interfaces are only 10 to 100 nanometers 

in thickness, making such techniques 

somewhat ineffective for imaging the 

interphase in composites. By installing the 

RS probe at the interface, the researchers 

were able to “see” damage exclusively at 

the interface using optical microscopy.

The NIST research team is planning to 

expand their research to explore how 

such probes could be used in other kinds 

of composites as well. They also would 

like to use such sensors to enhance 

the capability of these composites to 

withstand extreme cold and heat. There’s 

a tremendous demand for composites 

that can withstand prolonged exposure to 

water, too, especially for use in building 

more resilient infrastructure components 

such as bridges and giant blades for wind 

turbines.

The research team plans to continue 

searching for more ways that damage 

sensors such as the one in this study could 

be used to improve standards for existing 

composites and create new standards for 

the composites of the future, ensuring 

that those materials are safe, strong and 

reliable.

“We now have a damage sensor to help 

optimize the composite for different 

applications,” Gilman said. “If you 

attempt a design change, you can figure 

out if the change you made improved the 

interface of a composite, or weakened it.”

This research was funded through 

collaborative research agreements with 

both the Air Force Office of Scientific 

Research and the Army Research Office.

J.W. Woodcock, R. Beams, C.S. Davis, N. Chen, S.J. 

Stranick, D.U. Shah, F. Vollrath, and J.W. Gilman, 

Observation of Interfacial Damage in a Silk-Epoxy 

Composite, Using a Simple Mechanoresponsive Fluorescent 

Probe, Adv. Mater Interfaces 2017, 

http://dx.doi.org/10.1002/admi.201601018/abstract

|

Continued from page 8

Such nanoscale variations of the 

magnetization could become crucial to 

document, said Gilbert, for engineers 

trying to optimize the performance of a 

magnetic memory device. The variation 

in magnetization direction could also 

affect the ability of electron spin to flip 

the magnetization.

“Instead of flipping magnetization 

up or down, the spin current flips 

the magnetization along whatever its 

preferred local [spin] axis happens to 

be,” notes Gilbert. The variation in 

magnetization direction suggests that 

materials used for magnetic memory 

devices may need to be gently heated, a 

process that aligns nanoscale magnetic 

domains.

electrons are the dominant actors could 

suggest ways to minimize the current 

needed to flip the magnetization, Stiles 

said.

“Right now, we’re in the process of 

publicizing the model to experimentalists, 

trying to get them to use it to better 

understand their data,” he noted.

I. Gilbert, P.J. Chen, D.B. Gopman, A.L. Balk, D.T. 

Pierce, M.D. Stiles and J. Unguris, Nanoscale imaging 

of magnetization reversal driven by spin-orbit torque, 

Phys. Rev. B, 2016, http://dx.doi.org/10.1103/

PhysRevB.94.094429

V.P. Amin and M.D. Stiles, Spin transport at interfaces with 

spin-orbit coupling: Formalism, Phys. Rev. B, 2016, 

http://dx.doi.org/10.1103/PhysRevB.94.104419

V.P. Amin and M.D. Stiles, Spin transport at interfaces with 

spin-orbit coupling: Phenomenology, Phys. Rev. B, 2016, 

http://dx.doi.org/10.1103/PhysRevB.94.104420

In separate work, NIST scientists Mark 

Stiles and Vivek Amin, who has a joint 

appointment with the University of 

Maryland, focus on the theory describing 

the torque measured in the SEMPA 

experiments. There, a stream of polarized 

electrons generated in a nonmagnetic 

metal strip interacts with the 

magnetization of an overlying material. 

In particular, the team has developed a 

model that may help determine which 

group of polarized electrons play the more 

important role in reversing the direction 

of magnetization in adjacent material—

those originating at the surface of the 

nonmagnetic material or those from the 

interior.

The answer could guide the fabrication of 

more efficient magnetic memory devices. 

For instance, determining which group of 

|
1 2 |

|

‘START CODONS’ IN DNA AND RNA MAY BE MORE NUMEROUS THAN PREVIOUSLY 

THOUGHT

For decades, scientists working with 

genetic material have labored with a 

few basic rules in mind. To start, DNA 

is transcribed into messenger RNA 

(mRNA), and mRNA is translated into 

proteins, which are essential for almost all 

biological functions. A central principle 

regarding translation has long held that 

only a small number of three-letter 

sequences in mRNA, known as start 

codons, could trigger the production 

of proteins. But researchers might need 

to revisit and possibly rewrite this rule, 

after recent measurements from a team 

including scientists from NIST.

The findings, published in the journal 

Nucleic Acids Research by scientists in a 

research collaboration between NIST and 

Stanford University, demonstrate that 

there are at least 47 possible start codons, 

each of which can instruct a cell to begin 

protein synthesis. It was previously 

thought that only seven of the 64 possible 

triplet codons trigger protein synthesis.

“It could be that many potential start 

codons had remained undiscovered 

because no one could see them,” said lead 

author Ariel Hecht, a team member at the 

Joint Initiative for Metrology in Biology

(JIMB), a research collaboration that 

includes NIST and Stanford.

Scientists made many of their initial 

discoveries about DNA and RNA, 

including start codons, in the 1950s and 

1960s. Those ideas have since become 

enshrined in textbooks around the globe 

as the modern understanding of the rules 

of molecular biology.

Genetic code is typically represented via 

sequences of four letters—A, C, G, and T 

or U—which correspond to the molecular 

units known as adenine, cytosine, guanine 

and thymine (for DNA code) or uracil 

(for RNA code). Fifty years ago, the best 

available research tools indicated that 

there were only a few start codons (with 

sequences of AUG, GUG and UUG) 

in most living things. Start codons are 

important to understand because they 

mark the beginning of a recipe for 

translating RNA into specific strings of 

amino acids (i.e., proteins).

The JIMB team’s realization that there 

might be something amiss in the general 

understanding of how codons perform 

began unexpectedly over a round of bagels 

and coffee. Hecht and his colleagues 

Jeff Glasgow, Lukmaan Bawazer and 

Matt Munson were discussing colleague 

Paul Jaschke’s experiment where he had 

replaced the start codons of several genes 

of a virus PhiX174 with codons that 

should not have started translation (AUA 

and ACG). However, to Jaschke’s surprise, 

he was still detecting the expression 

of those genes that should have been 

silenced due to removal of their start 

codons.

Hecht and colleagues, together with 

Jaschke, pursued what seemed like 

a rather naive question: What if the 

results indicated that codons didn’t fit a 

traditional description of start or not, but 

instead had varying likelihoods to start 

Image of an agar plate streaked with 16 different strains of Escherichia coli, each containing a green fluorescent 

protein with a different start codon (annotated along the edge of the plate). The 16 codons correspond to the 16 

strongest expressing codons. Image is a composite of two super-imposed images from a laser scanner. 

Credit: Jeff Glasgow/Ariel Hecht/Kelly Irvine/NIST

translation? To the best of their knowledge, 

no one had ever systematically explored 

whether translation could be initiated from 

all 64 codons. No one had ever proved 

that you cannot start translation from any 

codon.

“We kind of all collectively asked ourselves: 

had anyone ever looked?” said Hecht. A 

further review of available literature on the 

topic indicated that the answer was no.

Unlike geneticists working a half-century 

ago, the JIMB team and others who peer 

into the inner workings of cells now have 

far more powerful tools at their disposal, 

including green fluorescent protein (GFP), 

a protein adapted from jellyfish, and 

nanoluciferase, another protein adapted 

from a deep sea shrimp. Both GFP and 

nanoluciferase emit light when expressed 

inside cells and have been optimized within 

the past decade to produce very strong 

signals that can be used to probe the cells 

in depth.
| 1 3

“Ten years ago the tools to make this kind 

of measurement didn’t exist,” Hecht said.

NIST specializes in the process of 

precision measurement, and the start 

codon challenge proved irresistible 

to the JIMB team. The collaboration 

was formed in 2016 with the goal of 

advancing biomeasurement science and 

facilitating the process of discovery by 

bringing together experts from academia, 

government labs and industry for 

collective scientific investigations.

With the use of GFP and nanoluciferase, 

the team measured translation initiation 

in the bacteria E. coli from all 64 codons. 

They were able to detect initiation of 

protein synthesis from 47 codons.

The implications of the work could be 

quite profound for our understanding of 

biology.

“We want to know everything going 

on inside cells so that we can fully 

understand life at a molecular scale 

and have a better chance of partnering 

with biology to flourish together,” said 

Stanford professor and JIMB colleague 

and advisor, Drew Endy. “We thought we 

knew the rules, but it turns out there’s a 

whole other level we need to learn about. 

The grammar of DNA might be even 

more sophisticated than we imagined.”

Still, the JIMB team cautions, this paper 

is really just the first step, and it is unclear 

what studies of other organisms will 

reveal.

“We need to be very careful about 

extrapolating from these findings or 

applying them to other organisms 

without further, deeper research,” said 

Hecht. He hopes that this paper will 

encourage or inspire other researchers 

to explore the topic to find even more 

answers.

“It could be that all codons could be start 

codons,” Hecht said. “I think it is just a 

matter of being able to measure them at 

the right level.”

Ariel Hecht, Jeff Glasgow, Paul Jaschke, Lukmaan Bawazer, 

et al., Measurements of translation initiation from all 64 

codons in E. coli., Nucleic Acids Res., 2017, 

http://dx.doi.org/10.1093/nar/gkx070

|

NIST TECHNOLOGY USED TO HELP IDENTIFY KEY ENZYMES IN DISEASE

Elephantiasis and river blindness are neglected tropical diseases caused by filarial 

nematode parasites that are transmitted to humans by insects. Collectively, they afflict 

150 million people in over 80 countries and threaten the health of over 1.5 billion. 

MML scientists recently contributed to a paper in the journal Nature Communications

that reports the discovery of a series of cyclic peptides and analogues that exhibit 

potent and isozyme-selective inhibition against enzymes essential for the parasites that 

cause elephantiasis and river blindness, but that are absent from humans. There are 

no high-throughput screening methods that can directly measure the activity of these 

key enzymes (phosphoglycerate mutases). So, the conventional approach uses two 

additional coupling enzymes to produce a color change in the inhibition screening 

assay. This can lead to problems if the apparent inhibition is due to a reaction of the 

drug molecule with the coupling enzymes instead of the targeted mutase enzyme. 

The NIH National Center for Advancing Translational Science (NCATS) approached 

NIST about the possibility of applying NIST technology to this problem. To verify 

the NCATS results, NIST scientists developed a method, based on gradient elution 

moving boundary electrophoresis, that directly measures the activity of the mutase 

enzymes.

The cyclic peptides and accompanying crystallographic information described in the 

paper reveal an important binding mode and inhibition mechanism for an enzyme 

previously considered ‘undruggable’ and may be applicable to other difficult drug 

targets.

Yu, H.; Dranchak, P.; Li, Z. R.; MacArthur, R.; Munson, M. S.; Mehzabeen, N.; Baird, N. J.; Battalie, K. P.; Ross, D.; 

Lovell, S.; Carlow, C. K. S.; Suga, H.; Inglese, J., Macrocycle peptides delineate locked-open inhibition mechanism for 

microorganism phosphoglycerate mutases, Nature Communications 8, 2017, http://dx.doi.org/10.1038/ncomms14932

POPULAR PROTEOMICS TOOL NOW INCORPORATES NIST MASS SPECTRAL 

SEARCH SOFTWARE

The newest release of Mascot, a popular proteomics software package, incorporates 

the peptide library search program MSPepSearch developed by the NIST Mass 

Spectrometry Data Center. Mass spectrometry is the most widely used discovery 

tool in proteomics and identification of proteins/peptides in a sample is the key 

first step. Mascot, maintained by Matrix Science Ltd, aims at determination of the 

precise identities of as many proteins/peptides as possible in each biological sample 

mass spectral data set. Prior versions of Mascot used simple theoretical fragmentation 

models of the peptide for identification. In the new release of Mascot, NIST’s 

MSPepSearch is incorporated to allow a faster, more reliable method for identifying 

peptides by matching them to spectra in a mass spectral library. This method also 

enables spectra for unusual and unpredictable spectra to be identified in the same way 

as conventional peptides. NIST has been a leader in developing spectral libraries for 

many years, including extensive libraries of peptides (http://peptide.nist.gov).
1 4 |

OUTREACH AND PARTNERING

LAUNCH OF THE HIGH-THROUGHPUT 

EXPERIMENTAL MATERIALS VIRTUAL 

LABORATORY

NIST and the National Renewable 

Energy Laboratory (NREL) have 

launched the High-Throughput 

Experimental Materials Virtual 

Laboratory (HTE-MVL), with the 

goal of generating the huge volumes 

of data needed to validate existing 

materials models and develop new, more 

sophisticated ones. The HTE-MVL will 

consist of a national network of highthroughput synthesis and characterization 

tools integrated into the Materials 

Genome Initiative (https://www.mgi.

gov) materials data infrastructure. The 

facility will foster coordination and 

data integration across high-throughput 

experimental programs. The result will 

be a widely accessible, growing resource 

open to the entire materials research 

community. 

The primary goal of the MGI is the 

discovery, optimization, and commercial 

deployment of novel materials twice as 

fast as today’s practice, and at reduced 

cost. Since its inception in 2011, 

the MGI has resulted in significant 

progress in computational simulation 

and modeling to enable predictions 

of materials properties. More recently, 

an experimental component, based on 

high-throughput experimental materials 

science, has been added. However, 

there remain serious challenges that the 

materials community must overcome 

to enable widespread deployment 

of an MGI-type approach to novel 

materials development. For example, 

data, both experimental and simulated, 

must be made discoverable, accessible, 

and interoperable. Further, even one 

“brick and mortar” high-throughput 

experimental facility would be very 

costly. The HTE-MVL was established in 

response to both challenges.

To promote the success of this project 

NIST and NREL are working on several 

fronts:

• Development of a conceptual model 

for integration of components within 

the materials data infrastructure 

consisting of: registries, repositories, 

data transfer services, laboratory 

information management systems, 

instruments, computing, and more.

• Development of a specialized registry 

and repository to enable discovery 

and access of items within the virtual 

laboratory, such as sample libraries, 

instruments, data, and more.

• Development of community 

interchange standards for data and 

metadata

• Execution of a round-robin 

experiment where transparent 

conducting oxide libraries are 

synthesized and characterized 

by both institutions and data is 

managed by the new materials data 

infrastructure. 

• Outreach to critical stakeholders, 

such as funding agencies, 

potential new member institutes, 

potential new users, potential new 

contributors, and potential new data 

consumers.

Green, M. L., Choi, C. L., Hattrick-Simpers, J. R., Joshi, 

A. M., Takeuchi, I., Barron, S. C., Campo, E., Chiang, 

T., Empedocles, S., Gregoire, J. M., Kusne, A. G., Martin, 

J., Mehta, A., Persson, K., Trautt, Z., Van Duren, J., and 

Zakutayev, A., Fulfilling the promise of the materials 

genome initiative with high-throughput experimental 

methodologies, Applied Physics Reviews 4, 2017, 

http://dx.doi.org/10.1063/1.4977487

FEDERAL MATERIALS SCIENCE LEADERS 

GATHER AT NIST

“How can federal scientists across agencies 

most effectively address pressing national 

needs?” Over 100 federal scientists 

convened at the Federal Interagency 

Materials Representatives meeting, held 

at the NIST Gaithersburg campus on 

February 1, 2017 to address this question. 

Participants included federal scientists 

from the U.S. Depts. of Commerce, 

Defense, Energy, and Transportation, 

NASA, the National Science Foundation, 

and more. Plenary speakers, including 

Linda Horton from Dept. of Energy, 

Basic Energy Sciences, Benjamin 

Leever from the Air Force Research 

Laboratory, and Heather Evans from 

NIST shared best practices and lessons 

learned for planning and managing 

government agency investments in 

science, engineering, and technology to 

enhance the impact of materials research 

in the U.S. Scientists discussed successes 

and challenges in strategic planning, 

coordination, research overlap, the 

connection between basic and applied 

research, and leveraging center- and 

institute-based research structures during 

breakout sessions. The annual meeting is 

open to federal scientists.
| 1 5

COLLABORATION TO UNDERSTAND 

ARMOR BACKING MATERIAL RHEOLOGY 

Behind-armor blunt trauma is a 

deformation in the ballistic witness 

material caused when armor stops 

a projectile from perforating armor. 

Understanding the rheological behavior 

of this material is critical for the future 

of both Department of Defense and 

civilian documentary standards that 

rely on ballistic witness materials for 

determination of compliance with 

requirements for behind-armor blunt 

trauma protection. Recently, members 

of MML’s Security Technologies 

Group hosted representatives from the 

Army Research Laboratory (ARL) in 

Aberdeen, Maryland and Aberdeen Test 

Center (ATC) to discuss rheological 

characterization of a potential new 

ballistic witness material being formulated 

by ARL and ATC designated as ARTIC. 

NIST will use new specialized technology 

to characterize the rheological properties 

of several candidate formulations of 

ARTIC. 

OUTREACH AND PARTNERING

REGENERATIVE MEDICINE STANDARDS 

COORDINATING BODY

More and larger companies are entering 

the regenerative medicine field through 

the development of cell therapies such 

as CAR-T. Standards play an important 

role in helping to assure the quality 

of regenerative medicine products 

and processes, and speed regulatory 

approval. The Standards Coordinating 

Body (SCB) is an industry-led publicprivate partnership with NIST to help 

coordinate standards development for 

regenerative medicine. Coordination is 

key considering the passage of the 21st 

Century Cures Act, which directs the 

U.S. Secretary of Health and Human 

Services to confer with NIST and other 

stakeholders to facilitate the coordination 

and prioritization of the development 

of standards for regenerative medicine. 

MML representatives recently met with 

representatives of the SCB to discuss 

priorities for carrying out the intentions 

of the agreement. The partnership with 

the SCB will be important as NIST 

determines how best to prioritize activities 

in this rapidly evolving field.

NIST/IBM COLLABORATIVE STUDY 

ON SELF-ASSEMBLED STRUCTURE 

PUBLISHED 

The journal Macromolecules recently 

published a paper by MML researcher 

Vivek Prabhu, with a colleague from the 

IBM Almaden Research Center, on block 

co-polymer self-assembled structure. 

The paper shows, through very detailed 

experiments, that the chemical nature 

of the end-group of a block co-polymer 

can strongly affect the microstructure 

of a self-assembled structure. Block 

copolymers are like surfactants in that 

one part of the molecule is different than 

the other (i.e. ‘likes’ oil or ‘likes’ water). 

These copolymers self-assemble into a 

variety of structures that are used in drug 

delivery, food products, or as microgels. 

The structure determines the properties 

such as the rate of a drug delivery. Here, 

the chemical nature of just the end group, 

a small part by mass, is strong enough to 

lead to many structural changes that are 

probed in detail. Link: https://dx.doi.

org/10.1021/acs.macromol.6b02524
1 6 |

AWARDS

NATARAJAN WINS FEI IMAGE AWARD

Bharath Natarajan, a NIST associate 

from Georgetown University working on 

the 3-D imaging of carbon and cellulose 

nanofibers in the Nanomanufacturing 

Program, submitted an image of a 3-D 

volume reconstruction of a forest of 

carbon nanotubes (CNT) embedded in 

epoxy, titled “A (CNT) bundle is strong.” 

The transmission electron microscopy 

(TEM) sample was prepared by focusing 

ion beam (FIB) milling in a FEI Helios 

FIB and imaged in an FEI Titan TEM 

using electron tomography. The tilt series 

was reconstructed and then processed 

using in-house software to identify CNT 

bundles and color them based on their 

size. This bundling information is key to 

understanding the network properties as 

well the axial mechanical properties of 

these composites.

Jack Glover, of MML’s Security Technologies Group, has received an ASTM F12 Award 

of Excellence in recognition of his efforts and accomplishments in developing the recent 

significant revision of the ASTM F792 “Standard Practice for Evaluating the Imaging 

Performance of X-ray Systems.” This revision included the design, development, and 

performance verification of the image quality artifact standards and of the algorithms 

used to compute the image quality parameter values. ASTM F792 is the major technical 

performance standard for testing cabinet X-ray systems, such as those used to screen 

carry-on baggage at airports. The standard was first published in 1982 and is used 

throughout the world for testing cabinet X-ray systems. For the first time in 15 years, 

the standard recently underwent a major revision. The working group, led by NIST 

researchers Jack Glover, Ron Tosh, Larry Hudson, and Nick Paulter, also included 

representatives from the governments of Germany, UK, Brazil, and Australia as well as 

U.S. agencies such as the Department of Homeland Security, Transportation Security 

Administration, and Federal Bureau of Prisons and numerous equipment manufacturers. 

This revision of the standard was a major improvement and was necessary to keep pace 

with the evolving technology at the checkpoint. The F12 Award of Excellence was 

established in 1997 and is conferred, as warranted, by Committee F12 on Security 

Systems and Equipment in recognition of meritorious contributions to the cause of 

voluntary standardization, specifically with respect to security systems and equipment 

standards. The award has been established to recognize outstanding service to 

Committee F12.

GLOVER RECEIVES ASTM AWARD

BEST PAPER AWARD FROM THE MICROSCOPY SOCIETY OF AMERICA

The Microscopy Society of America recently recognized a NIST/University of Arizona authored paper (led by MML’s Vladimir Oleshko) 

as the best paper in the Materials Applications category. The paper is entitled, “Analytical Multimode Scanning and Transmission 

Electron Imaging and Tomography of Multiscale Structural Architectures of Sulfur Copolymer-Based Composite Cathodes for Next 

Generation High-Energy Density Li-S Batteries” (Microsc. Microanal. 22, 1198-1221). Microscopy and Microanalysis is an international 

microscopy journal published for the Microscopy Society of America (MSA) by Cambridge University Press. It is the official journal of 

the Microscopy Society of America, Microanalysis Society, and several other societies. Each year the journal selects the best paper in three 

different categories: Materials Applications, Biological Applications, and Techniques and Equipment Development. The award will be 

presented to Oleshko at the Microscopy and Microanalysis 2017 Meeting by Ian Anderson, President of MSA. 
| 1 7

NIST GUEST RESEARCHER HONORED WITH LITHUANIA NATIONAL SCIENCE PRIZE

On March 7, 2017, Gintaras Valinčius, division chief at the Biochemical Institute of 

Vilnius University and NIST guest researcher, was awarded the Lithuania National 

Science Prize. Valinčius was recognized for his indefatigable commitment to research/

science development in Lithuania and the European Union, teaching at Vilnius 

University, and his seminal contributions to electrochemistry and electrochemical 

impedance to spectroscopy (EIS) in particular. The National Science Prize is one 

of the top prizes awarded to scientists in Lithuania and has been called ‘Lithuania’s 

Nobel Prize.’ Valinčius has a long history of collaborative research with NIST and the 

Institute of Bioscience and Biotechnology Research. Valinčius first came to NIST 

as a visiting scientist in 1998 and has returned nearly every year to conduct research 

focused on hybrid bilayer membrane and tethered bilayer lipid membranes. Using 

tether compounds synthetically prepared by retired NIST employee, Dave Vanderah, 

Valinčius carried out careful EIS measurements demonstrating the preparation of 

highly insulating lipid bilayers, essential for the study of integral membrane proteins, 

which comprise 60% of all drug targets by the pharmaceutical industry. Together 

they have co-authored 14 papers since 2003. Over the last three years, Valinčius has 

developed the first theoretical framework that allows EIS spectral data to be interpreted 

in more realistic structural models rather than the less informative resistancecapacitance circuit models.

TARLOV DELIVERS MEMORIAL LECTURE AT UMD 

SCHOOL OF PHARMACY ANNUAL RESEARCH DAY

On April 12, 2017, MML Division Chief Michael 

Tarlov gave the Andrew G. DuMez Memorial 

Lecture at the University of Maryland School of 

Pharmacy in Baltimore, held during their annual 

research day. Tarlov’s talk was entitled “The Role of 

Measurements and Standards in the Development 

and Manufacturing of Biopharmaceuticals.” After the 

talk, Natalie Eddington, Dean of the UMD School of 

Pharmacy, presented Tarlov with an honorary award. 

AWARDS

COBLE ELECTED FELLOW OF THE 

AMERICAN ACADEMY OF FORENSIC 

SCIENCE

Mike Coble of MML’s Applied Genetics 

Group was recently elected Fellow of the 

American Academy of Forensic Science 

(AAFS) at their 2017 annual meeting. 

AAFS is a multi-disciplinary professional 

organization that provides leadership to 

advance science and its application to 

the legal system. The objectives of the 

Academy are to promote professionalism, 

integrity, competency, and education, 

and foster research, improve practice, and 

encourage collaboration in the forensic 

sciences. Over the past 16 years, Coble 

has been an active member in AAFS, 

presenting his work on DNA mixture 

analysis, and acting as moderator, student 

presentation judge, and workshop leader. 

The leadership of AAFS recognized these 

contributions and Coble’s substantial 

contributions to the forensic science 

literature and training regarding DNA 

mixture analysis with the honor of Fellow.
1 8 |

MEASUREMENT SCIENCE FOR INFRASTRUCTURE RENEWAL

NIST helps pipeline operators realize the safety benefits and cost-savings of new high-strength 

steel alloys.

MML MEASURES UP

NIST’s Material Measurement Laboratory 

provides new test methods and data to 

inform improved design methods, material 

choices, and industry standards for fossil

fuel pipelines. We have unique facilities 

for measuring steel properties as specimens 

are pulled, bent, or otherwise stressed, like 

they might be in actual service. Our data 

informs computer models that predict how 

new, stronger steels behave under various 

conditions, contributing to the safe use of 

thinner walled pipes that are more costeffective. We’re also leading an effort to 

reduce the need for expensive, full-scale 

pipe bursting tests with laboratory-scale 

test methods that significantly reduce costs, 

and our research on pipeline welds is being 

used to revise American Pipeline Institute 

standards.

We have a history of success in 

contributing to new standards and codes 

that benefit industry while maintaining 

safety: NIST’s tests on the pipeline steel 

used to transport hydrogen, a plentiful 

and clean burning fuel that can help the 

U.S. become less dependent on foreign 

petroleum, led to a code change that 

allowed hydrogen pipeline owners to 

switch to stronger, thin-walled pipes 

without increased cost. The stronger steel 

means that pipelines can be larger in 

diameter and move hydrogen at higher 

pressures, so more hydrogen can be 

transported faster and safer.

A sample of high-strength X70 steel pulled apart by

NIST testing.

> 2.5 million miles of pipelines cross all 50 U.S. states to transport natural 

gas, liquid petroleum products, and other chemicals critical to our energy 

infrastructure and economy 

> $5.3 billion in total costs and 885 deaths and injuries from significant 

pipeline incidents since 2005

> $100 million saved by energy companies by avoiding unnecessary 

shutdowns thanks to data from NIST research that confirms assessment 

methods for vintage pipelines. More than 50% of the pipelines in the 

U.S. are made of older grades of steel
| 1 9

PUBLICATIONS

B. Natarajan, C.D. Emiroglu, J. 

Obrzut, D. M. Fox, B. A. Pazmino, J. 

F. Douglas, J. W. Gilman, “Dielectric 

Characterization of Confined Water in 

Chiral Cellulose Nanocrystal Films” ACS 

Applied Materials and Interfaces, 10, (10-

Apr-2017) 

H. Ma, A. Killaars, F. W. DelRio, C. 

Yang, K. S. Anseth, “Myofibroblastic 

activation of valvular interstitial cells 

is modulated by spatial variations in 

matrix elasticity and its organization” 

Biomaterials, Vol. 131, pp. 131-144, 

(05-Apr-2017) 

W. E. Wallace, W. Ji, D. V. Tchekhovskoi, 

K. W. Phinney, S. E. Stein, “Mass Spectral 

Library Quality Assurance by InterLibrary 

Comparison” Journal of the American 

Society for Mass Spectrometry, Vol. 28, No. 

4, pp. 733-738, (02-Apr-2017) 

E. R. Sisco, M. N. Najarro, D. V. 

Samarov, J. A. Lawrence, “Quantifying 

Stability of Trace Explosives under 

Different Environmental Conditions” 

Talanta, Vol. 165, pp. 10-17, (01-Apr2017) 

D. W. Siderius, N. Mahynski, V. K. 

Shen, “Relationship between Pore-size 

Distribution and Flexibility of Adsorbent 

Materials: Statistical Mechanics and 

Future Material Characterization 

Techniques” Adsorption, Vol. 23, pp. 

593-602, (30-Mar-2017) 

J. W. Woodcock, R. Beams, C. S. Davis, 

S. J. Stranick, D. U. Shah, F. Vollrath, J. 

W. Gilman, “Interfacial damage sensing 

and cure monitoring in a silk-epoxy 

composite using a mechanochromic 

probe” Advanced Materials, (19-Mar2017) 

C. G. Simon Jr., N. A. Hotaling, 

“Nanofiber Scaffold Based Tissue 

Engineered Retinal Pigment Epithelium 

to Treat Degenerative Eye Diseases” 

Amerasia Journal, Vol. 32, No. 5, pp. 272-

285, (01-Mar-2017) 

M. R. Stoudt, R. E. Ricker, E. Lass, L. 

E. Levine, “The Influence of Post-Build 

Microstructure on the Electrochemical 

Behavior of Additively Manufactured 

17-4 PH Stainless Steel” JOM Journal of 

the Minerals Metals and Materials Society, 

Vol. 69, No. 3, pp. 506-515, 

(01-Mar-2017) 

H. H. Kong, B. Andersson, T. Clavel, J. 

E. Common, S. A. Jackson, N. D. Olson, 

J. Segre, C. Traidl-Hoffman, “Performing 

skin microbiome research: A method 

to the madness” Journal of Investigative 

Dermatology, Vol. 137, No. 3, pp. 561-

568, (01- Mar-2017) 

N. Mahynski, M. A. Blanco Medina, J. R. 

Errington, V. K. Shen, “Predicting lowtemperature free energy landscapes with 

flathistogram Monte Carlo methods” The 

Journal of Chemical Physics, Vol. 146, 16, 

(21-Feb-2017)

J. W. Sowards, E. A. Pfeif, M. J. 

Connolly, J. D. McColskey, S. L. Miller, 

B. J. Simonds, J. R. Fekete, “Low-Cycle 

Fatigue Behavior of Fiber-Laser Welded, 

Corrosion-Resistant, High-Strength Low 

Alloy Sheet Steel” Materials and Design, 

Vol. 121, No. 5, pp. 393-405, (21-Feb2017) 

M.M. Dizdar, E. Coskun, P. Jaruga, 

“Repair of Oxidatively Induced 

DNA Damage by DNA Glycosylases: 

Mechanisms of Action, Substrate 

Specificities and Excision Kinetics” 

Mutation Research-Reviews in Mutation 

Research, (16-Feb-2017) 

R. E. Cavicchi, C. Collett, S. Telikepalli, Z. 

Hu, M. J. Carrier, D. C. Ripple, “Variable 

Threshold Method for Determining the 

Boundaries of Imaged Subvisible Particles” 

Journal of Pharmaceutical Sciences, 9, 

(15-Feb-2017) 

N. Mast, K. W. Anderson, J. Lin, Y. Li, 

I. V. Turko, C. Tatsuoka, I. Bjorkhem, I. 

A. Pikuleva, “Cytochrome P450 27A1 

Deficiency and Regional Differences in 

Brain Sterol Metabolism Cause Preferential 

Cholestanol Accumulation in the 

Cerebellum” Journal of Biological Chemistry, 

(11-Feb-2017)

W. B. Wilson, L. C. Sander, J. O. Ona 

Ruales, S. Mossner, L. M. Sidisky, M. 

Lee, S. A. Wise, “Retention behavior of 

alkylsubstituted polycyclic aromatic sulfur 

heterocycle isomers in gas chromatography 

on stationary phases of different selectivity” 

Journal of Chromatography A, pp. 73-84, 

(10-Jan-2017) 
2 0|

|

The Material Measurement Laboratory supports the NIST mission by serving as the national 

reference laboratory for measurements of matter, providing broad support for chemical, 

biological, and materials sciences. Our fundamental and applied measurement science 

research expands possibilities for determining the composition, structure, and properties 

of manufactured, biological, and environmental materials, and the processes that create 

them. In addition, MML drives the development and dissemination of tools—including 

measurement protocols, certified reference materials, critically evaluated data, and best 

practice guides—that help assure quality measurements of matter. Our research and 

measurement services support progress in areas of national importance including advanced 

materials, energy, environment, food safety and nutrition, forensic science, health care, 

manufacturing, physical infrastructure, and safety and security. MML also coordinates the 

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TO LEARN MORE, CONTACT:

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Gaithersburg, MD 20899-8300

Tel: 301-975-8300

mmlinfo@nist.gov

or visit http://www.nist.gov/mml