From the Director __________________________________________
My decision to step down as SSRL Director was announced earlier this month.
Serving as Director has been a great opportunity that I have embraced with
enthusiasm. I have grown personally and professionally as a consequence and I
am thankful for the opportunity to lead such an excellent science organization.
As Director, I have gained new skill and experience; I have also developed a
refined understanding of how I can best serve science. It has been gratifying
to play a part in strengthening collaboration across directorates and
divisions, supporting research from applied energy programs and battery
research to chemistry and catalysis. Guided by this experience, I have
chosen to transition to the Chemical Sciences Division Director role at SLAC
starting February 1 and look forward to continued interactions with the SSRL
community moving forward.
Paul McIntyre, the Rick and Melinda Reed Professor at the School of
Engineering at Stanford University, has been selected as the next director of
SSRL and will begin his appointment on July 1. Paul received his ScD from
the Massachusetts Institute of Technology in 1993. He was a postdoctoral fellow
at MIT and Los Alamos National Laboratory, and served as a technical staff
member at Texas Instruments, Inc., before joining Stanford University in
1997.
A professor of Materials Science and Engineering, Paul has served as chair
of the Materials Science and Engineering Department since 2014. He is a senior
fellow of the Precourt Institute for Energy, and from 2008 to 2013, he
served as director of the Geballe Laboratory for Advanced Materials, a Stanford
independent laboratory for interdisciplinary materials research. Paul
currently leads a research team investigating nanostructured inorganic
materials for electronics and energy technologies. A long-time user of SSRL,
his expertise and experience will bring new research directions to the lab.
Piero Pianetta, Deputy Director of SSRL, will serve as interim director
until Paul assumes the directorship in July.
Science
Highlights _________________________________________
Shared-Ligand Intermediates of Metal Exchange Visualized by Rapid
Freeze Quench and Selenium EXAFS of Se-Labeled Metallochaperones. A Paradigm
for Studying Copper-Mediated Host-Pathogen Interactions –
Contacts: Ninian Blackburn, Oregon Health & Sciences University, and
Kelly Chacón, Reed College
To defend against infections, our phagocyte cells form a vesicle called a
phagosome around pathogens, which then merges with a lysosome to form a
phagolysosome. To terminate the threat, the phagolysosome gives the invading
cell toxic doses of copper. However, some bacteria have evolved mechanisms for
pumping the copper back out of the cell, avoiding toxicity. Understanding the
enzymes involved in these complicated processes is important to our
understanding of disease. Read more...
Copper Mobilization and Immobilization along an Organic Matter and
Redox Gradient – Insights from a Mofette Site –
Contacts: Britta Planer-Friedrich and Judith Mehlhorn, Bayreuth University,
Germany
While a small amount of copper is essential for living organisms, too much
copper contaminating our soils can be toxic and pose a serious problem. Copper
has an affinity for organic matter in soils, where it mainly exists in the two
redox states Cu(I) and Cu(II). In soils that fluctuate in redox conditions, the
mobility of copper through the environment can be hard to predict. Mofette
sites, produced by CO2 degassing usually found in seismically active
areas, are good natural laboratories due to their wide range of soil redox
conditions and of soil organic matter composition within a small area. Near the
sites of CO2 degassing, the soil is anoxic and organic matter does
not decompose well. The soils transition to oxic conditions just a few meters
away. A team of researchers studied the behavior of copper in the natural
gradient of a mofette site in the Czech Republic. Read more...
 | |
A Structural Switch that Couples TCR Ligand Binding to
Signaling – Contacts: Chris Garcia and Leah Sibener,
Stanford University
T cells allow our immune system to respond to specific antigens from
infectious agents. Each T cell hosts a receptor (TCR) that binds to a
particular antigenic peptide ligand. If the receptor is exposed to the ligand
it recognizes, the T cell is activated. A team of researchers used a variety of
methodologies including protein engineering, x-ray crystallography, single
molecule techniques, and molecular simulations to understand how T cells
recognize their ligands and subsequently how T cells are activated. Read more...
Evolution of the Nanoporous Structure of Sintered Ag at High
Temperature Using in-Situ X-ray Nanotomography – Contacts:
Yijin Liu, SSRL and Xavier Milhet, Institut Pprime, France
Many new electronic devices replace traditional silicon chips with silicon
carbide (SiC) semiconductor chips, which are able to handle more power,
function with less power loss, and operate at higher temperatures. Because
these chips generate more heat, new materials that bond the chip to the heat
sink are needed. A promising choice is sintered silver (Ag). However, detailed
and quantitative information about the pore structure and evolution during
aging of sintered Ag have not been well studied. A team of researchers
quantitatively analyzed the pore structure of sintered silver at high
temperatures over time. Read more...
SSRL-Related News ________________________________________
Study Shows Single Atoms can Make More Efficient
Catalysts
Excerpt from January 7, 2019 SLAC News Feature article by Glennda
Chui
Catalysts are chemical matchmakers: They bring other chemicals close
together, increasing the chance that they’ll react with each other and
produce something people want, like fuel or fertilizer.
Since some of the best catalyst materials are also quite expensive, like the
platinum in a car’s catalytic converter, scientists have been looking for
ways to shrink the amount they have to use.
Using four approaches – infrared spectroscopy, electron microscopy,
theoretical calculations and x-ray spectroscopy on Beam Line 6-2 at SSRL
scientists now have their first direct, detailed look at how a single atom
catalyzes a chemical reaction. The reaction is the same one that strips
poisonous carbon monoxide out of car exhaust, and individual atoms of iridium
did the job up to 25 times more efficiently than the iridium nanoparticles
containing 50 to 100 atoms that are used today. The research team, led by
Ayman M. Karim of Virginia Tech, reported the results in Nature Catalysis. Read more...
SSRL Users' Executive Committee Update
_______________________
UEC Election Results
Please join us in supporting Graham George and Timothy Stemmler as the new
Chair and Vice-Chair of the Users' Executive Committee. We are pleased to
welcome new members Michael Capano, Bor-Rong Chen, Amy Cordones-Hahn, and
Arianna Gleason (Ex Officio, LCLS UEC). We would like to
acknowledge the contributions of David Bushnell (2018 Chair) and the entire UEC
in support of SSRL this past year and extend our thanks to retiring committee
members Feng Lin, Lisa Mayhew, Mariano Trigo and Christoph Bostedt (Ex
Officio, LCLS Past Chair). And, we would like to express our appreciation
to Eddie Snell and James P. Evans who will remain on the committee after
standing for election.
Upcoming Events and Courses ________________________________
SSRL Resonant Inelastic X-ray Scattering with Hard X-rays Workshop
February 20-22, 2019
SSRL will conduct a Resonant Inelastic X-ray Scattering with Hard X-rays
workshop between February 20 and February 22. The three-day session will
include lectures and tutorials on hard x-ray RIXS with focus on experimental
details and in-depth data analysis and interpretation methods using both
experimental fingerprints and detailed theoretical descriptions. Examples will
be highlighted in various scientific fields. Advanced registration is required
by February 15. workshop website
U.S. Particle Accelerator School June 17-28, 2019
The next program of the university-style credit courses will be sponsored by
the University of New Mexico to be held in Albuquerque, New Mexico on June
17-28, 2019. website
Joint SSRL/LCLS Users’ Conference September 25-27, 2019
– Call for Workshop Topics by March 18
We are beginning to plan for the next joint SSRL/LCLS Users' Conference
to be held here at SLAC September 25-27, 2019, and we need your input!
Please send us suggestions for full or half-day workshop topics for the
conference. Include a working title, brief description of the science area or
topics that could be discussed, and potential organizers. We would also
appreciate your suggestions for keynote talks or potential speakers. Please
contact SSRL UEC members or the User Office to share your input.
EMSL Integration 2019 – Plants, Soil and Aerosols:
Interactions that tell stories of Ecosystems, Climate and National
Security” October 8-10, 2019 announcement
Announcements
__________________________________________
New Instrument at LCLS for MeV-Electron Diffraction for Ultrafast
Science Applications (MeV-UED)
Since 2014, the UED instrument team has been developing robust methods in
the pursuit of time-resolved measurements to control and understand molecular
structural dynamics and the coupling of electronic and nuclear motions in a
variety of material and chemical systems. MeV-UED’s first external user
experimental time on the Solid State (Materials) & Warm Dense Matter
(Single Shot) Endstation has been announced for mid 2019. MeV-UED Instrument Page
A virtual MeV-UED meeting (webcast) will be held Tuesday, February
19 at 8:30 am to inform the community about developments at MeV-UED before the
upcoming MeV-UED proposal deadline on March 12. For more information
on MeV-UED, please contact the instrument experimental points of contact:
Xiaozhe Shen, Alex Reid, and Ming-Fu Lin
User Research Administration
_______________________________
Beam Time Request Deadline
- February 1, 2019 – X-ray / VUV (May - July scheduling)
SSRL Proposal Deadlines
- April 1, 2019 – Macromolecular Crystallography
- May 1, 2019 – X-ray / VUV
See SSRL Proposal & Scheduling Guidelines and submit proposals and beam time requests through the User
Portal.
New Mothering Pod near Experimental Floor
At the request of several users, we have created a dedicated mothering room
at SSRL. This new Mamava pod is located next to BL9-2 behind the user
kitchen/lounge.
_____________________________________________________________________
The Stanford Synchrotron Radiation Lightsource (SSRL) is a third-generation
light source producing extremely bright x-rays for basic and applied
research. SSRL attracts and supports scientists from around the world who
use its state-of-the-art capabilities to make discoveries that benefit society.
SSRL, a U.S. DOE Office of Science national user facility, is a Directorate of
SLAC National Accelerator Laboratory, operated by Stanford University for the
U.S. Department of Energy Office of Science. The SSRL Structural
Molecular Biology Program is supported by the DOE Office of Biological and
Environmental Research, and by the National Institutes of Health, National
Institute of General Medical Sciences. For more information about SSRL science,
operations and schedules, visit http://www-ssrl.slac.stanford.edu.
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Questions? Comments? Contact
Lisa Dunn
