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National Biomedical Center
for Advanced Electron Spin Resonance Technology

Our research is supported by a grant from the National Institute of General Medical Sciences (NIGMS), part of the National Institutes of Health.


News Archive

last update:   June 7, 2018


Detailed information and URL links for registration / lodging are now available HERE for the 2018 ACERT Denoising Workshop, to be held at ACERT's home Cornell University in Ithaca, NY, on July 30-31, 2018.


The workshop has been scheduled to immediately follow the Rocky Mountain Conference on Magnetic Resonance so as to simplify travel concerns for conference attendees, especially those coming from Europe. (There will be a brief talk about the denoising methods at the Thursday-Friday workshop at the end of the conference.) Please remember that the ACERT workshop is hands-on: all participants are encouraged to bring raw data sets from their labs to be processed during the course of the workshop.

April, 2018: About the Revolutionary New Denoising Methods

At ACERT we are excited by the revolutionary new denoising methods we have introduced into the processing of ESR spectra, both cw and time domain. These wavelet-based denoising methods, outlined in our publications (1,2), have led to decreases in the data-acquisition time required for ESR data of one to two orders of magnitude; and our associated SVD (singular value decomposition)-based method for determining distance distributions in ESR data, as outlined in publication 3, has likewise allowed researchers to see multiple conformations that hitherto were hidden due to noise and poor resolution from previously-available regularization methods. We are working on how to expand the applicability of the new methods to other types of magnetic resonance applications.

1. M. Srivastava, C.L. Anderson, and J.H. Freed. "A New Wavelet Denoising Method for Selecting Decomposition Levels and Noise Thresholds" IEEE Access 4, 3862-3877 (2016). (Link: PDF)

2. M. Srivastava, E.R. Georgieva, and J.H. Freed. "A New Wavelet Denoising Method for Experimental Time-Domain Signals: Pulsed Dipolar Electron Spin Resonance" J. Phys. Chem. A 121, 2452-2465 (2017). (Links: PDF, Supplement)

3. M. Srivastava and J. H. Freed. "Singular Value Decomposition Method to Determine Distance Distributions in Pulsed Dipolar Electron Spin Resonance" J. Phys. Chem. Lett. 8, 5648-5655 (2017). (Links: PDF, Supplement)

September, 2017--New ACERT X/Q Pulsed ENDOR Spectrometer Facility.

In June, 2017, a state-of-the-art Bruker Elexsys-II E580 X/Q-Band pulsed Electron-Nuclear Double Resonance (ENDOR) ESR spectrometer was installed at the NIH P41-funded National Biomedical Center for Advanced ESR Technology (ACERT) at Cornell University, housed in the Department of Chemistry and Chemical Biology. Research groups at Cornell, the University of Rochester, SUNY Buffalo, and other future collaborating institutions can now use this modern commercial instrument. ACERT possesses the necessary expertise and technical capability to maintain the facility, which is unique in the Northeastern US.

ACERT, since its establishment in 2001, provides EPR expertise and service to many research groups nationally, which represent many biomedical fields. While the EPR currently performed in ACERT has been crucial in obtaining structural and functional information on paramagnetic cofactors in biological systems such as iron sulfur clusters, copper active sites etc., additional studies using ENDOR were often necessary but not available at Cornell for such users. Having an ENDOR shared capability at Cornell housed in ACERT will dramatically improve the quality of research for the groups participating in this proposal, as well as others who interact with ACERT. Facility users will have direct control of their ENDOR measurements, which will become part of their daily research. Also, importantly, ENDOR and EPR studies can now be carried out at the same time on the same samples and under the same conditions. As described below in the projects of major/minor users, ENDOR and EPR (e.g. ESEEM) are complementary to each other in terms of revealing different aspects of interactions between the unpaired electron and nuclear spins present in biological systems under study.

There are currently five major user groups planning to use our proposed ENDOR spectrometer, as well as additional minor users. The NIH-supported research projects of the major users include: (1) ENDOR study of novel chemistry of a [4Fe-4S]-cluster containing radical enzyme in diphthamide biosynthesis; (2) ENDOR and Electron-Spin Echo Envelope Modulation (ESEEM) to probe the role of hydration in membrane fusion; (3) ENDOR spectroscopy studies of proteins that mediate signal transduction through redox and photochemistry; (4) mechanism of inhibition of ribonuclease reductase by anti-cancer drugs; and (5) structure and dynamics of porphysomes — new photosensitive agents in cancer therapy and drug delivery. Additional projects from minor users include: (6)structure and function of artificial hydrogenases; (7) nitrification of enzymes and electron transfer proteins; and (8) hydration at lipid surfaces. Given the growing interest in ENDOR we also anticipate additional users.

The ACERT Elexsys-II ENDOR system is user-friendly and suitable for multiple users with a range of spectrometer configuration requirements. The types of user-friendly operations available at ACERT allow a rapid feedback between the expression, design, or synthesis of the system of interest and the analysis of its detailed structural parameters. For this reason, it was deemed appropriate to establish a fast-throughput ENDOR capability at ACERT, motivated by an initial group of key biomedical investigators. The good resolution for ENDOR at Q-band is a very important advantage of the proposed system. At the higher fields associated with Q-band frequencies, orientational spectra are spread over an almost 4 times larger range of frequencies than at X-band. This increases the ENDOR experiment's sensitivity to and resolution of small structural changes, in turn improving the quality of results for important biological applications of ESR, such as the determination of structures and mechanisms of enzyme catalytic centers.

July, 2017--Prof. Jack H. Freed is named a Fellow of the IES (International Electron spin/paramagnetic resonance) Society at their July 23-28 Quebec City meeting.

A Fellowship of the Society may be conferred on individuals who have made influential and distinguished contributions to the practice of EPR (ESR) Spectroscopy and its welfare over a long period.

June, 2017--Prof. Jack H. Freed is awarded the Voevodsky Prize during the IXth Voevodsky conference in Novosibirsk, Russia, June 25-30.

The Voevodsky Prize is awarded once every two years, in the memory of Academician V. V. Voevodsky of the Institute of Chemical Kinetics and Combustion of the Siberian Branch of the Russian Academy of Sciences and the International Tomography Center. The Prize is awarded to Russian and foreign scientists, in turn, for outstanding contributions to the investigation of mechanisms of chemical reactions, structure and properties of active intermediates, and elementary reactions in photo- and radiation chemistry by radiospectroscopic methods.

Awarding of the Voevodsky Prize is based on a competition. Candidates are nominated by scientific institutes or by individual scientists. The final decision is made by an Award Committee, consisting of 7 members. Members of the Committee are selected by the Scientific Council of the Institute of Chemical Kinetics and Combustion and are renewed each five years. The Voevodsky Prize is presented either at the session of the Scientific Council of the Institute of Chemical Kinetics and Combustion or during the conference dedicated to the memory of V. V. Voevodsky. An Awardee is expected to participate in these meetings and deliver a lecture on his scientific work.


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