Monday, September 30, 2013

Open position at Bridge12: Engineer (entry-level)

Bridge12 has currently an opening for an engineer (entry level). We are looking for a junior engineer to support our team at our facilities in Framingham (MA, USA).
Your tasks will include:
  • ·       Mechanical design using state-of-the-art 3D CAD software
  • ·       Preparation of engineering drawings
  • ·       Work on the product assembly and testing
  • ·       Documentation of design process
  • ·       Requesting quotes for manufacturing and negotiate pricing with suppliers
  • ·       Preparing manufacturing cost estimates for parts and subassemblies


This is an entry-level position and applications of recent college graduates are encouraged. For more information visit: http://www.bridge12.com/content/open-position-engineer-entry-level

Hyperpolarized butyrate: A metabolic probe of short chain fatty acid metabolism in the heart


Ball, D.R., et al., Hyperpolarized butyrate: A metabolic probe of short chain fatty acid metabolism in the heart. Magn Reson Med, 2013: p. n/a-n/a.


Butyrate, a short chain fatty acid, was studied as a novel hyperpolarized substrate for use in dynamic nuclear polarization enhanced magnetic resonance spectroscopy experiments, to define the pathways of short chain fatty acid and ketone body metabolism in real time. METHODS: Butyrate was polarized via the dynamic nuclear polarization process and subsequently dissolved to generate an injectable metabolic substrate. Metabolism was initially assessed in the isolated perfused rat heart, followed by evaluation in the in vivo rat heart. RESULTS: Hyperpolarized butyrate was generated with a polarization level of 7% and was shown to have a T1 relaxation time of 20 s. These physical characteristics were sufficient to enable assessment of multiple steps in its metabolism, with the ketone body acetoacetate and several tricarboxylic acid cycle intermediates observed both in vitro and in vivo. Metabolite to butyrate ratios of 0.1-0.4% and 0.5-2% were observed in vitro and in vivo respectively, similar to levels previously observed with hyperpolarized [2-13 C]pyruvate. CONCLUSIONS: In this study, butyrate has been demonstrated to be a suitable hyperpolarized substrate capable of revealing multi-step metabolism in dynamic nuclear polarization experiments and providing information on the metabolism of fatty acids not currently achievable with other hyperpolarized substrates. Magn Reson Med, 2013. (c) 2013 Wiley Periodicals, Inc.

Friday, September 27, 2013

Press Release: NIH Funds Development of Integrated THz System, Making DNP-NMR Spectroscopy More Affordable

Press Release

NIH Funds Development of Integrated THz System, Making DNP-NMR Spectroscopy More Affordable
Bridge12’s SBIR Fast-Track Grant Will Eliminate Need for Second Superconducting Magnet, Greatly Reducing Cost for Dynamic Nuclear Polarization


Framingham, Mass. – September 27th, 2013 – Bridge12 Technologies, a leading provider of terahertz (THz) technology for applications in science, medicine, security, and defense, announces it secured Phase I of a National Institute of Health’s (NIH) small business innovation research (SBIR) fast-track grant totaling $1.2 million over 3 years for the development of an Integrated THz system for DNP-NMR spectroscopy that eliminates the need for a second superconducting magnet, reducing the cost of DNP-NMR instrumentation by more than $0.8 million per spectrometer. Dynamic Nuclear Polarization (DNP) can increase the sensitivity of a NMR experiment by several orders of magnitude, accelerating experiments that typically require weeks to complete in minutes.

Nuclear magnetic resonance (NMR) spectroscopy is used broadly across many disciplines, such as analytical chemistry, structural biology or drug discovery and scientists that are using NMR spectroscopy are often challenged by the low sensitivity of NMR, which slows down research and increases research costs. In recent years, Dynamic Nuclear Polarization (DNP) has proven to be highly successful in increasing sensitivity in solid-state NMR experiments, achieving enhancement factors of > 200 at 400 MHz (1H Larmor Frequency) corresponding to a factor of 40,000 in time savings. In other words, an experiment that typically requires days or weeks of signal averaging can be performed in minutes or hours. This significantly increased overall sensitivity will accelerate NMR experiments for analytical applications or the structural characterization of bio-macromolecules or catalyst surfaces.

To efficiently drive the DNP process, scientists require high-power, high-frequency THz sources such as gyrotrons that can generate sufficient THz power. As a result, a conventional DNP-NMR system requires two superconducting magnets: one for the NMR experiment and another for the gyrotron. This makes DNP systems extremely expensive. The new Bridge12 project is focused on the development of a novel DNP system based on a THz source that is integrated into the superconducting NMR magnet. This is possible because wide-bore NMR magnets provide sufficient space right above the NMR probe to integrate and operate the gyrotron source. This novel, innovative gyrotron tube is specifically designed for DNP applications, providing sufficient power and has adequate frequency tuning bandwidth to eliminate the superconducting sweep coil that is necessary in other DNP systems. Eliminating the second superconducting magnet can save research groups more than $ 0.8 million per spectrometer, making DNP a much more affordable method. Currently predominantly used in the academic domain, the invention will make DNP-NMR a realistic options for industry researchers. The first prototype probe will be designed to operate at an NMR spectrometer frequency of 400 MHz but the technology is expected to work at NMR frequencies above 600 MHz.

“In recent years DNP has become an important method to increase the sensitivity in a NMR experiment,” says Dr. Thorsten Maly, Bridge12 co-founder and principal investigator for the project. “However, the high costs are prohibitive, especially for young researchers to enter this exciting new research field. Eliminating the superconducting magnet for the gyrotron will greatly reduce the acquisition and operating costs of a DNP-NMR system.. This will make DNP-NMR more affordable, especially for young-investigators/scientists entering the field. DNP is a young research field, so putting instrumentation within economic reach is important to enable research and increase the pace of innovation.”
“Gyrotrons were initially developed for heating plasma in nuclear fusion experiments, which requires megawatts of millimeter wave power and gyrotrons that are currently used in DNP-NMR spectroscopy are often downscaled versions of these devices. However, such high levels of power are not necessary for DNP-NMR,” says Dr. Jagadishwar Sirigiri, a Bridg12 founder and principal investigator for the project. “For this project we took a fresh new look at all components required in the DNP-NMR experiment. This allowed us to develop a novel concept for a gyrotron tube, specifically designed for DNP which will lead to more cost-effective system. ”

Phase I of this SBIR fast-track grant was awarded from the National Institute of General Medical Sciences (NIGMS), part of the National Institute of Health (NIH), in the amount of US$ 198,888 over a one-year period. The complete budget for the combined Phase I and II is 1.2 Million US$ over a period of 3 years.

About Bridge12
Bridge12 Technologies develops terahertz technology for applications in science, medicine, security and defense. Overcoming current technology barriers, the company closes the ‘terahertz gap’ with compact sources that are powerful, efficient, and rapidly deployable. Bridge12 Technologies’ solutions help accelerate scientific research, protect national security, and fight terminal diseases.

Bridge12 is a high-tech start-up founded by former scientists of the Massachusetts Institute of Technology (MIT). Its scientific team has several decades of combined expertise in high-frequency terahertz (THz) sources such as gyrotrons, microwave technology, and magnetic resonance spectroscopy. The executive team combines know-how of over 3 decades in project management, information technology, health care, and consumer products. For more information, visit www.bridge12.com.
###
Media Contact Information
Dr. Thorsten Maly
Director, Bridge12 Technology Inc.
Phone: +1 (617) 615-9332
Email: tmaly@bridge12.com

Design and implementation of an FPGA-based timing pulse programmer for pulsed-electron paramagnetic resonance applications


This article has not much to do with DNP, however, it is a very nice article about instrumentation for magnetic resonance spectroscopy and since DNP is still often an area where researchers use a lot of home-built equipment I'm sure there will be folks interested in that.



Sun, L., J.J. Savory, and K. Warncke, Design and implementation of an FPGA-based timing pulse programmer for pulsed-electron paramagnetic resonance applications. Concepts in Magnetic Resonance Part B: Magnetic Resonance Engineering, 2013. 43(3): p. 100-109.


The design, construction, and implementation of a field-programmable gate array (FPGA)-based pulse programmer for pulsed-electron paramagnetic resonance experiments is described. The FPGA pulse programmer offers advantages in design flexibility and cost over previous pulse programmers, which are based on commercial digital delay generators, logic pattern generators, and application-specific integrated circuit designs. The FPGA pulse progammer features a novel transition-based algorithm and command protocol, which is optimized for the timing structure required for most pulsed magnetic resonance experiments. The algorithm was implemented by using a Spartan-6 FPGA (Xilinx), which provides an easily accessible and cost effective solution for FPGA interfacing. An auxiliary board was designed for the FPGA-instrument interface, which buffers the FPGA outputs for increased power consumption and capacitive load requirements. Device specifications include: Nanosecond pulse formation (transition edge rise/fall times, ≤3 ns), low jitter (≤150 ps), large number of channels (16 implemented; 48 available), and long pulse duration (no limit). The hardware and software for the device were designed for facile reconfiguration to match user experimental requirements and constraints. Operation of the device is demonstrated and benchmarked by applications to one-dimensional electron spin echo envelope modulation and two-dimensional hyperfine sublevel correlation (HYSCORE) experiments. The FPGA approach is transferrable to applications in nuclear magnetic resonance (magnetic resonance imaging), and to pulse perturbation and detection bandwidths in spectroscopies up through the optical range. © 2013 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 43B: 100-109, 2013

Wednesday, September 25, 2013

Congratulations to Patrick van der Wel for receiving the 2013 EAS New Faculty Award in NMR Spectroscopy

From the Ampere Magnetic Resonance List:



The EAS is pleased to announce that the recipient of the 2013 EAS New Faculty Award in NMR Spectroscopy is Dr. Patrick van der Wel.


Patrick van der Wel is an assistant professor in the Department of Structural Biology of the University of Pittsburgh School of Medicine. He received his undergraduate degree in Chemistry at Utrecht University in the Netherlands, and his PhD degree in Chemistry & Biochemistry at the University of Arkansas, in Fayetteville. He then pursued his postdoctoral research in the lab of Professor Robert Griffin at the Massachusetts Institute of Technology, before joining the faculty of the University of Pittsburgh in 2008.

Dr. van der Wel’s scientific interests focus on the development and application of solid-state NMR spectroscopy for studies of biological systems. During his undergraduate and graduate research, he applied solid-state NMR to address basic biophysical and structural processes that govern protein-lipid interactions. Specifically, he probed the molecular interplay between hydrophobic mismatch and transmembrane helix tilt and how proteins or peptides can modulate membrane curvature.

His postdoctoral research in the Griffin lab centered on magic-angle-spinning methods that permitted him to address an expanded array of biological and biophysical questions. His work focused on both the methodological aspects of solid-state NMR and the applications to determine protein structure and dynamics, including the application of low-temperature dynamic nuclear polarization (DNP) to amyloid-related samples and on the effect of low temperatures on protein dynamics and solid-state NMR spectra. Using various magic angle spinning methods, Dr. van der Wel characterized structure and in particular, the internal conformations, of amyloid fibrils.

At the University of Pittsburgh, his lab uses an array of solid-state NMR measurements of site-specific structure as well as dynamics to further our understanding of protein-membrane interactions and amyloid formation. A particular focus has been on the aggregation process associated with polyglutamine expansion in Huntington’s disease and related disorders. Dr. van der Wel has published more than 30 papers, covering topics ranging from amyloid formation and structure, to membrane biophysics, to low-temperature DNP, to magic angle spinning and oriented-membrane solid-state NMR spectroscopy.

Mark your calendars:
The award, sponsored by Agilent Technologies, Inc., will be presented at the EAS meeting on Tuesday, November 19th from 2 to 5 pm.

Tatyana Polenova, 2013 Awards Chair
Eastern Analytical Symposium
Visit us at: http://eas.org

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Large Molecular Weight Nitroxide Biradicals Providing Efficient Dynamic Nuclear Polarization at Temperatures up to 200 K


Zagdoun, A., et al., Large Molecular Weight Nitroxide Biradicals Providing Efficient Dynamic Nuclear Polarization at Temperatures up to 200 K. J. Am. Chem. Soc., 2013. 135(34): p. 12790-12797.


A series of seven functionalized nitroxide biradicals (the bTbK biradical and six derivatives) are investigated as exogenous polarization sources for dynamic nuclear polarization (DNP) solid-state NMR at 9.4 T and with ca. 100 K sample temperatures. The impact of electron relaxation times on the DNP enhancement (ε) is examined, and we observe that longer inversion recovery and phase memory relaxation times provide larger ε. All radicals are tested in both bulk 1,1,2,2-tetrachloroethane solutions and in mesoporous materials, and the difference in ε between the two cases is discussed. The impact of the sample temperature and magic angle spinning frequency on ε is investigated for several radicals each characterized by a range of electron relaxation times. In particular, TEKPol, a bulky derivative of bTbK with a molecular weight of 905 g·mol?1, is presented. Its high-saturation factor makes it a very efficient polarizing agent for DNP, yielding unprecedented proton enhancements of over 200 in both bulk and materials samples at 9.4 T and 100 K. TEKPol also yields encouraging enhancements of 33 at 180 K and 12 at 200 K, suggesting that with the continued improvement of radicals large ε may be obtained at higher temperatures.

Monday, September 23, 2013

Population transfer for signal enhancement in pulsed EPR experiments on half integer high spin systems


Kaminker, I., et al., Population transfer for signal enhancement in pulsed EPR experiments on half integer high spin systems. Phys Chem Chem Phys, 2009. 11(31): p. 6799-806.


High resolution pulse EPR techniques applied to half integer high spin systems, such as Mn(2+) (S = 5/2), usually focus only on the central |-1/2--> |1/2 transition. The reason is that at high fields, where the zero field splitting is considerably smaller than the Zeeman interaction, the spectrum of this transition is intense and narrow. However, because the experiments are carried out at low temperatures, the low lying levels are heavily populated and the signal of the central transition is nevertheless diminished. This, in turn affects the sensitivity of the pulse EPR technique applied. A transfer of populations from the lower lying levels, which for Mn(2+) are the |-3/2 and |-5/2 levels, to the |-1/2 level will therefore increase the sensitivity. Here we describe such an experiment, where a rapid magnetic field sweep over the |-3/2--> |-1/2 sub-spectrum is carried out, concomitantly with a low power microwave (mw) irradiation, which results in population inversion. After this sweep any pulsed EPR sequence can be applied to the central transition that now has a population difference that deviates from the equilibrium value. The feasibility of the experiment is demonstrated at W-band (95 GHz) on Mn(2+) doped in MgO for echo-detected EPR measurements and the dependence of the signal enhancement on the rate and range of the magnetic field sweep and on the mw power is described. The results are then accounted for theoretically by considering a simple fictitious spin 1/2 system. In addition, preliminary enhanced (55)Mn pulse ENDOR electron nuclear double resonance (ENDOR) spectra are presented.

Friday, September 20, 2013

A Well-Defined Pd Hybrid Material for the Z-Selective Semihydrogenation of Alkynes Characterized at the Molecular Level by DNP SENS


Conley, M.P., et al., A Well-Defined Pd Hybrid Material for the Z-Selective Semihydrogenation of Alkynes Characterized at the Molecular Level by DNP SENS. Chemistry, 2013. 19(37): p. 12234-8.


Direct evidence of the conformation of a Pd-N heterocyclic carbene (NHC) moiety imbedded in a hybrid material and of the Pd-NHC bond were obtained by dynamic nuclear polarization surface-enhanced NMR spectroscopy (DNP SENS) at natural abundance in short experimental times (hours). Overall, this silica-based hybrid material containing well-defined Pd-NHC sites in a uniform environment displays high activity and selectivity in the semihydrogenation of alkynes into Z-alkenes.

Wednesday, September 18, 2013

Improved Structural Elucidation of Synthetic Polymers by Dynamic Nuclear Polarization Solid-State NMR Spectroscopy


Ouari, O., et al., Improved Structural Elucidation of Synthetic Polymers by Dynamic Nuclear Polarization Solid-State NMR Spectroscopy. ACS Macro Letters, 2013. 2(8): p. 715-719.


Dynamic nuclear polarization (DNP) is shown to greatly improve the solid-state nuclear magnetic resonance (SSNMR) analysis of synthetic polymers by allowing structural assignment of intrinsically diluted NMR signals, which are typically not detected in conventional SSNMR. Specifically, SSNMR and DNP SSNMR were comparatively used to study functional polymers for which precise structural elucidation of chain ends is essential to control their reactivity and to eventually obtain advanced polymeric materials of complex architecture. Results show that the polymer chain-end signals, while hardly observable in conventional SSNMR, could be clearly identified in the DNP SSNMR spectrum owing to the increase in sensitivity afforded by the DNP setup (a factor ?10 was achieved here), hence providing access to detailed structural characterization within realistic experimental times. This sizable gain in sensitivity opens new avenues for the characterization of ?smart? functional polymeric materials and new analytical perspectives in polymer science.

Monday, September 16, 2013

Manufacturing of a 263 GHz continuously tunable gyrotron


Rozier, Y., et al. Manufacturing of a 263 GHz continuously tunable gyrotron. in Vacuum Electronics Conference (IVEC), 2013 IEEE 14th International. 2013.


A 263 GHz gyrotron dedicated to Dynamic Nuclear Polarization (DNP) enhanced Nuclear Magnetic Resonance (NMR) spectroscopy has been designed by EPFL and manufactured by Thales. With this device, we have demonstrated an output power up to 160 W in continuous wave. Design and main experimental results are discussed in this paper.

Friday, September 13, 2013

Cross-polarisation edited ENDOR


Rizzato, R., et al., Cross-polarisation edited ENDOR. Mol. Phys., 2013: p. 1-15.


Abstract Electron nuclear double resonance is a fundamental technique in EPR spectroscopy that directly detects hyperfine transitions of nuclei coupled to a paramagnetic center. Despite its wide use, spin-sensitivity and restricted spectral resolution in powder samples pose limitations of this technique in modern application fields of EPR. In this contribution we examine the performance of an ENDOR pulse sequence that utilizes a preparation scheme different from conventional Davies ENDOR. The scheme is based on electron-nuclear cross polarization (eNCP), which requires concomitant microwave (MW) and radio-frequency (RF) irradiation satisfying specific matching conditions between the MW and RF offsets and the hyperfine coupling. Changes in nuclear polarization generated during eNCP can be detected via a conventional ENDOR read-out sequence consisting of a RF π-pulse followed by EPR-spin echo detection. Using 1H BDPA as a standard sample, we first examine the CP matching conditions by monitoring the depolarization of the electron spin magnetization. Subsequently, so-called CP-edited ENDOR spectra for different matching conditions are reported and analyzed based on the provided theoretical description of the time evolution of the spin density matrix during the experiment. The results demonstrate that CP-edited ENDOR provides additional information with respect to the sign of the hyperfine couplings. Furthermore, the sequence is less sensitive to nuclear saturation effects encountered in conventional ENDOR.

Wednesday, September 11, 2013

The Observation and Dynamics of 1H NMR Spin Noise in Methanol


Jurkiewicz, A., The Observation and Dynamics of 1H NMR Spin Noise in Methanol. Appl. Magn. Reson., 2013: p. 1-18.


The observation of 1H spin noise in relation to prior established mag- netization and radiation damping has revealed a correlated dynamics. The spin noise of methyl satellites in 13C-enriched methanol was observed in the presence of an antiphase magnetization, created by the combination of 1H–13C J coupling evolution and radiofrequency (RF) ulses. A gradient pulse was applied to remove residue spin coherence coming from the RF pulses, and as a result spin noise phenomena were uncovered. While magnetization was in an inverted metastable state, the spin– spin relaxation time was shortened to prevent a super radiation burst. The relation between magnetization, radiation amping, and absorption or emission of the spin noise of methyl satellites has been studied. In relation to agnetization and radiation damping, spin noise bump and dip have been observed simultaneously in the same molecule. Both can be created through a proper inversion of magnetization. The revealed spin noise dynamics of spin system coupling to the probe circuit via radiation damping allows performance of a transformation from dip into bump by proper application of pulses combined with 1H–13C J coupling evolution.

Monday, September 9, 2013

TGIR NMR Users Meeting October 24, 2013 in Bordeaux

Dear colleagues,

The 5th annual TGIR NMR-THC Users Meeting will be held on October 24,2013 in Bordeaux. As in previous meetings, this day is an opportunity to present recent results and new developments, and also to review the operation of TGIR NMR-THC. For the full conference, we are pleased to welcome Professor Mark Baldus (Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands)

"NMR-based structural biology enhanced by ultra-high field DNP" 

The program will be finalized soon. You can already register on our website:


Looking forward to seeing you in Bordeaux

Chers collègues, 

Nous organisons la 5ème réunion des utilisateurs du TGIR-RMN-THC le 24 Octobre 2013 à Bordeaux.Comme pour les réunions précédentes cette journée sera l'occasion de vous présenter des résultats récents, de nouveaux développements et de faire le point sur le fonctionnement du TGIR-RMN-THC. Pour la conférence plénière, nous aurons le plaisir d'accueillir le Professeur Mark Baldus (Bijvoet Center for Biomolecular Research, Utrecht University, Pays-Bas) pour une conférence intitulée 

" NMR-based structural biology enhanced by ultra-high field DNP " 

Le programme sera finalisé prochainement et nous vous remercions de vous inscrire sur notre site internet :


A bientôt à Bordeaux


Erick Dufourc, Bernhard Brutscher, Lyndon Emsley, Eric Guittet, Guy Lippens, Frank Fayon, Anne Lesage et Jean-Pierre Simorre

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Solid-state NMR enhanced by dynamic nuclear polarization as a novel tool for ribosome structural biology


Gelis, I., et al., Solid-state NMR enhanced by dynamic nuclear polarization as a novel tool for ribosome structural biology. J. Biomol. NMR, 2013. 56(2): p. 85-93.


The impact of Nuclear Magnetic Resonance (NMR) on studies of large macromolecular complexes hinges on improvements in sensitivity and resolution. Dynamic nuclear polarization (DNP) in the solid state can offer improved sensitivity, provided sample preparation is optimized to preserve spectral resolution. For a few nanomoles of intact ribosomes and an 800 kDa ribosomal complex we demonstrate that the combination of DNP and magic-angle spinning NMR (MAS-NMR) allows one to overcome current sensitivity limitations so that homo- and heteronuclear 13C and 15N NMR correlation spectra can be recorded. Ribosome particles, directly pelleted and frozen into an NMR rotor, yield DNP signal enhancements on the order of *25-fold and spectra that exhibit narrow linewidths, suitable for obtaining site-specific information. We anticipate that the same approach is applicable to other high molecular weight complexes.

Friday, September 6, 2013

Temperature dependence of high field 13C dynamic nuclear polarization processes with trityl radicals below 35 Kelvin


Walker, S.A., et al., Temperature dependence of high field 13C dynamic nuclear polarization processes with trityl radicals below 35 Kelvin. Phys. Chem. Chem. Phys., 2013.


In order to facilitate versatile applications with high field dynamic nuclear polarization (DNP), it is important to be able to optimize the DNP performance, i.e. reach high nuclear hyperpolarization within a short signal build up time. Given that the solid-state DNP process is strongly temperature-dependent, it is important to benchmark the temperature dependence of various DNP and electron paramagnetic resonance (EPR) parameters that can then be used to test and develop theories and models for high field DNP mechanisms. However, DNP and EPR experiments at high fields and cryogenic temperatures below 20 Kelvin usually require home built instrumentation, and therefore even basic experimental observations are lacking in the literature. DNP and EPR experiments at 7 T (197 GHz) and 8.5 T (240 GHz), respectively, were conducted at temperatures between 35 K and 3.7 K where the electron thermal polarization changes from 13.4% to 85.6%, respectively. The samples are frozen solutions of 15 mM OX063Me trityl radicals in various mixtures of [1-13C]pyruvic acid, glycerol, and Gd3+-chelates. For all sample mixtures, the trityl EPR lines are found to be inhomogeneously broadened and the dominant DNP mechanism is shown to be the cross effect (CE). A 20%, 11%, and 6.77% 13C polarization is achieved at 3.7 K with a [1-13C]pyruvic-glycerol-H2O sample, the addition of 2 mM of Gd3+-chelates, and pure [1-13C]pyruvic acid, respectively. When T1n is sufficiently long, our results seem to suggest T1e is a key variable in the DNP process, where longer T1e values correlate with larger DNP enhancements (?DNP). The experimental data reported here on the temperature dependence of T1n, T1e, Tm (electron phase memory time), the EPR linewidth, TDNP and ?DNP at high fields will be helpful for testing the mechanism and theory of DNP processes.

Wednesday, September 4, 2013

[NMR] Course on "Dissolution Dynamic Nuclear Polarization" November 13-15, 2013 at EPFL, Switzerland

From the AMPERE list:



We would like to announce a three-day course for PhD students and Post-Docs on

"Dissolution Dynamic Nuclear Polarization"

The course will start at 1pm on Wednesday November the 13th and will end at 5pm on Friday 15th, and will be held at the Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland, at the Laboratory of Biomolecular Magnetic Resonance (LRMB).

* Registration
please register at the following adress:
http://inscription.epfl.ch/index.php?form=PhD_course_on_DNP
subscription fees: 100 CHF

* Information
geoffrey.bodenhausen (at) epfl.ch
sami.jannin (at) epfl.ch

* Objectives
Dissolution Dynamic Nuclear Polarization (D-DNP) provides a way to enhance NMR signals in liquids by more than 4 orders of magnitude. We present the current state-of-the-art and most recent advances of this technique, and we propose experimental demonstrations with hands-on participation.

* Content
Lectures and seminars: 11 Hours
Hands-on: 7 Hours
Day 1: Lectures, 1 pm - 5 pm: Theoretical aspects of DNP
- Introduction to DNP-enhanced NMR
- Principles of Dissolution-DNP
- Low temperature DNP mechanisms
- Cross Polarization techniques
- Applications to imaging and chemistry

Day 2: Lectures, 9 am - 12 am: Experimental aspects of DNP
- Hardware for DNP
- Hardware for Cross Polarization
- Hardware for Dissolution

Experiments, 1 pm - 5 pm
- Sample Preparation
- Preparation of a dissolution DNP experiment

Day 3: Experiments, 9 am - 12 am: Practical DNP at the Laboratory of Biomolecular Magnetic Resonance (LRMB)
- Low temperature DNP
- Cross Polarization with DNP
- Dissolution DNP

Seminars, 1 pm - 5 pm

- All participants are invited to give a short presentation, possibly on DNP and/or related to their own research subjects.

*Required prior knowledge
Basic understanding of NMR

Sami Jannin
Laboratory of Biomolecular Magnetic Resonance (LRMB)

Paper mail:
EPFL
LRMB - ISIC - SB
BCH 1534 (Bâtiment de chimie UNIL)
CH-1015 Lausanne
Switzerland

Phone +41 21 693 97 24
Fax +41 21 693 94 35

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Large Molecular Weight Nitroxide Biradicals Providing Effi-cient Dynamic Nuclear Polarization at Temperatures up to 200 Kelvin


Zagdoun, A., et al., Large Molecular Weight Nitroxide Biradicals Providing Efficient Dynamic Nuclear Polarization at Temperatures up to 200 K. J Am Chem Soc, 2013. 135(34): p. 12790-7.


A series of seven functionalized nitroxide biradicals (the bTbK biradical and six derivatives) are investigated as exogenous polarization sources for dynamic nuclear polarization (DNP) solid-state NMR at 9.4 T and with ca. 100 K sample temperatures. The impact of electron relaxation times on the DNP enhancement (epsilon) is examined, and we observe that longer inversion recovery and phase memory relaxation times provide larger epsilon. All radicals are tested in both bulk 1,1,2,2-tetrachloroethane solutions and in mesoporous materials, and the difference in epsilon between the two cases is discussed. The impact of the sample temperature and magic angle spinning frequency on epsilon is investigated for several radicals each characterized by a range of electron relaxation times. In particular, TEKPol, a bulky derivative of bTbK with a molecular weight of 905 g.mol(-1), is presented. Its high-saturation factor makes it a very efficient polarizing agent for DNP, yielding unprecedented proton enhancements of over 200 in both bulk and materials samples at 9.4 T and 100 K. TEKPol also yields encouraging enhancements of 33 at 180 K and 12 at 200 K, suggesting that with the continued improvement of radicals large epsilon may be obtained at higher temperatures.

Monday, September 2, 2013

First tests of a 527 GHz gyrotron for dynamic nuclear polarization


Felch, K., et al. First tests of a 527 GHz gyrotron for dynamic nuclear polarization. in Vacuum Electronics Conference (IVEC), 2013 IEEE 14th International. 2013.


A gyrotron operating at the second cyclotron harmonic in a magnetic field of 9.7 T has produced a CW output power of 25 W at 527 GHz. The gyrotron is now being employed in Dynamic Nuclear Polarization (DNP) Applications. The gyrotron design and results of the tests are presented.