Science Highlight

Significantly Shorter Fe-S Bond in Cytochrome P450-I is Consistent with Greater Reactivity Relative to Chloroperoxidase – Contact: Courtney Roach (Krest), SSRL

Bonds between carbon and hydrogen atoms are ubiquitous in organic molecules important for life.  Generally considered to be unreactive, C-H bonds are not easily activated so that the hydrogen can be replaced with a different chemical group. A mechanism that would allow chemists to selectively activate C-H bonds to become reactive would open up numerous new possibilities for synthetic chemistry and is the subject of intense interest.  Read more...

Citation: C. M. Krest et al., Nat. Chem., 03 August 2015 (10.1038/nchem.2306)

More SSRL-related Science

Microscopic Rake Doubles Efficiency of Low-cost Solar Cells

Excerpted from August 12, 2015 SLAC News Feature

Researchers have developed a manufacturing technique that could double the electricity output of inexpensive solar cells by using a microscopic rake when applying light-harvesting polymers.

When commercialized, this advance could help make polymer solar cells an economically attractive alternative to those made with much more expensive silicon-crystal wafers.

In experiments, solar cells made with the tiny rake doubled the efficiency of cells made without it and are 18 percent better than cells made using a microscopic straightedge blade.

The research was led by Zhenan Bao, a chemical engineering professor at Stanford and a member of the Stanford Institute for Materials and Energy Sciences (SIMES), which is joint between SLAC and Stanford.

“The fundamental scientific insights that come out of this work will give manufacturers a rational approach to improving their processes, rather than relying simply on trial and error,” Bao said.

“We also expect this simple, effective and versatile concept will be broadly applicable to making other polymer devices where properly aligning the molecules is important.”  Read more...

Citation:  Y. Diao et al., Nat. Commun., 12 August 2015 (10.1038/ncomms8955)

Structural Studies could Aid in Better Drug Design

Excerpted from The Scripps Research Institute August 31, 2015 News & Views

For the first time, researchers have uncovered the structural details of how some proteins interact to turn two different signals into a single integrated output. These new findings could aid future drug design by giving scientists an edge in fine tuning the signal between these partnered proteins—and the drug’s course of action.

“Thyroid, vitamin D and retinoid receptors all rely on integrated signals—their own signal plus a partner receptor,” said TSRI Associate Professor Kendall Nettles, who led the study with TSRI colleague Associate Professor Douglas Kojetin. “These new findings will have important implications for drug design by clearly defining exactly how these signals become integrated, so we will be able to predict how changes in a drug’s design could affect signaling.”  Read more...

Citation: D. J. Kojetin et al., Nat. Commun., 20 August 2015 (10.1038/ncomms9013)

X-ray Duo's Research Helps Launch Human Trial for Treatment of Arsenic Poisoning

Excerpted from August 20, 2015 SLAC News Feature

Graham George and Ingrid Pickering, a husband and wife x-ray research team, have worked for decades to understand how contaminants in water and soil are taken up by the body and affect human health. Much of that research has taken place at SSRL, where both are former staff scientists.

Now George and Pickering are co-leading a new study in Bangladesh that is testing whether giving people selenium supplements can protect them from arsenic poisoning caused by naturally contaminated drinking water, which affects more than 100 million people worldwide and can lead to cancer, liver disease and other severe health problems.

The clinical trial, which runs through July 2016, is paid for by the Canadian federal government and is sponsored by the University of Saskatchewan, where Pickering and George have been professors since 2003.

The idea for the treatment dates back to the 1930s, when a scientist discovered that rats fed wheat containing enough selenium to kill them could actually survive if they were also given arsenic-contaminated water.

Decades later, Jürgen Gailer, a scientist at the University of Calgary in Canada who was conducting related research on this biological oddity, asked Pickering and George if they could use x-ray techniques to find out how combining these two toxins could seemingly cancel out their dangerous effects in mammals.  Read more...

SSRL Users' Organization Update

Mark your calendar and plan to participate in the SSRL/LCLS Users’ Meeting and Workshops October 7-10, 2015 as well as the combined SSRL and LCLS Users' Organization discussion with facility management, scheduled to take place on Thursday, October 8.

Please take a few minutes to consider throwing your hat into the ring or nominating candidates interested in standing for election to the SSRL Users' Executive Committee to fill vacancies in the following areas:

• Materials/Chemistry
• Environmental/Geosciences
• Macromolecular Crystallography
• Ultrafast Science

Send your nominations via email to Cathy Knotts or submit using the online nomination form by September 30.  A ballot will be compiled and voting will take place the week of October 6 during the Users' Conference.

The SSRL UEC welcomes your comments, feedback and suggestions. We look forward to seeing you at the Annual Users' Meeting.

Upcoming Workshops and Conferences

– Joint SSRL/LCLS Annual Users' Conference, October 7-10, 2015

Register to attend the joint SSRL/LCLS Annual Users' Conference on October 7-10. To get started, click on "Create an Account". The $175 registration fee covers meeting logistics, light refreshments and lunch. The registration fee is waived for students and postdocs who register to present a poster and share their latest research or development projects.

The activities scheduled over this multi-day event provide opportunities to learn about the latest user research results, current/future capabilities and new science opportunities as well as to interact with other scientists and vendors of light source related products and services. Meeting highlights include:

• Director's Welcome and Facility Updates
• Invited Plenary Session Talks --
  Patricia Dehmer (DOE):  Perspectives on the Office of Science after 20 Years in Washington
  Axel Brunger (Stanford U):  Using LCLS to Determine the Crystal Structure of a Complex that is Central to Synaptic Neurotransmitter Release
  Stefano Bonetti (Stockholm U):  Spin Currents:  The Key to Nanometer and Femtosecond Magnetism
  Matt Kanan (Stanford U):  Chemical and Electrochemical CO₂ Recycling
• Michael Lubell (CCNY/American Physical Society): Thinking Big and Outside the Box
• Lytle, Spicer and Klein Award Presentations
  Feng Lin (Lawrence Berkeley National Laboratory) -- 2015 Spicer Young Investigator
• User Science Poster 'Blitz,' Poster Session and Reception
• Exhibitors of synchrotron-related equipment, supplies or services
• Focused Workshops

The plenary session talks, award presentations, exhibits, user poster session and reception will be held on October 8. Several parallel workshops are scheduled for October 7, 9, 10.

Wednesday, October 7, 2015 – Parallel Workshops

• Applications of Ptychography
• Beyond SASE at the LCLS & LCLS-II
• Characterization of Ultrafast Magnetization Dynamics Using X-rays
• Coupled Cycling of Biogeochemical Critical Elements and Contaminants
• Hybrid Methods for Integrative Structural Biology (Oct 6 at ALS, Oct 7 at SLAC)
• Time Resolved Studies with Femtosecond X-ray Pulses:  Towards Molecular Movies of Molecules at Work

Friday, October 9, 2015 – Parallel Workshops

• Advances in High Resolution X-ray Spectroscopy
• Attosecond FELs:  Capturing the Dynamics of Electrons in the Time Domain
• LCLS Data Collection, Diagnostics, Analysis, Interpretation
• New Discoveries in Biology with XFELS
• Probing Structure and Dynamics of Quantum Materials via X-ray Scattering at LCLS
• Science Opportunities at SLAC in the Tender X-ray Range (2-5 keV) (Oct 9-10)
• Scientific Opportunities with PS-Pulses at SSRL
• Single Particle Imaging Initiative: Year One

Please encourage colleagues, particularly students, to attend and present a poster.   Visit the conference website for the latest program details.

– Symposium 'Celebrating Artie Bienenstock', October 10, 2015

Please join us on Saturday, October 10, for a special symposium to honor Arthur Bienenstock. This symposium is scheduled immediately following the SSRL/LCLS Annual Users' Conference and Workshops. There is no registration fee to attend this symposium but separate registration is required. During the registration process, participants also have the option of signing up to attend a dinner honoring Artie (dinner cost is $50 per person).

– ALS Users' Meeting, October 5-7, 2015 – Berkeley, CA

User Research Administration

Proposal Deadlines

• September 1 is the deadline for submitting new X-ray/VUV proposals for beam time eligibility starting February 2016.

Fall Beam Time Request Deadlines

• September 17 is the next deadline for Macromolecular Crystallography Beam Time Requests covering mid-November through February
• November 15 is the next X-ray/VUV Beam Time Request deadline for February - May scheduling

Submit proposals and beam time requests through the user portal.

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