Hyperpolarized 13C MR spectroscopic imaging can detect not only the uptake of the pre-polarized molecule but also its metabolic products in vivo, thus providing a powerful new method to study cellular metabolism. Imaging the dynamic perfusion and conversion of these metabolites provides additional tissue information but requires ...

The ability to accelerate the spatial encoding process during a chemical shift imaging (CSI) scan of hyperpolarized compounds is demonstrated through parallel imaging. A hardware setup designed to simultaneously acquire (13)C data from multiple receivers is presented here. A system consisting of four preamplifiers, ...

The low sensitivity of 13C spectroscopy can be enhanced using dynamic nuclear polarization. Detection of hyperpolarized [1-13C]pyruvate and its metabolic products has been reported in kidney, liver, and muscle. In this work, the feasibility of measuring 13C signals of ...

High polarization of nuclear spins in liquid state through hyperpolarized technology utilizing dynamic nuclear polarization has enabled the direct monitoring of (13)C metabolites in vivo at a high signal-to-noise ratio. Acquisition time limitations due to T(1) decay of the hyperpolarized signal require accelerated imaging methods, such ...

We describe a novel 13C enriched precursor molecule, sodium 1-13C acetylenedicarboxylate, which after hydrogenation by PASADENA (Parahydrogen and Synthesis Allows Dramatically Enhanced Nuclear Alignment) under controlled experimental conditions, becomes hyperpolarized ...

Dynamic hyperpolarized [1-(13)C]pyruvate metabolic imaging in the normal anesthetized rat brain is demonstrated on a clinical 3-T magnetic resonance imaging scanner. A 12-second bolus injection of hyperpolarized [1-(13)C]pyruvate is imaged at a 3-second temporal resolution. ...

Dynamic nuclear polarization can be used to increase the sensitivity of solution state (13)C magnetic resonance spectroscopy by four orders of magnitude. We show here that [1-(13)C]glutamate can be polarized to 28%, representing a 35,000-fold increase in its sensitivity to detection at 9.4 T and 37�C. The metabolism of hyperpolarized ...

High polarization of nuclear spins in liquid state through dynamic nuclear polarization has enabled the direct monitoring of 13C metabolites in vivo at very high signal-to-noise, allowing for rapid assessment of tissue metabolism. The abundant SNR afforded by this hyperpolarization technique makes high-resolution 13C 3D-MRSI feasible. ...

A new method was developed for simultaneous spatial localization and spectral separation of multiple compounds based on a single echo, by designing the acquisition to place individual compounds in separate frequency encoding bands. This method was specially designed for rapid and robust metabolic imaging of hyperpolarized 13C ...

A new method was developed for simultaneous spatial localization and spectral separation of multiple compounds based on a single echo, by designing the acquisition to place individual compounds in separate frequency encoding bands. This method was specially designed for rapid and robust metabolic imaging of hyperpolarized (13)C ...

We show here that hyperpolarized [1-(13) C]pyruvate can be used to detect treatment response in a glioma tumor model; a tumor type where detection of response with (18) fluoro-2-deoxyglucose, using positron emission tomography, is limited by the high background signals from normal brain tissue. (13) ...

Dynamic nuclear polarization (DNP) is an emerging technique for dramatically increasing the sensitivity of magnetic resonance spectroscopy (MRS). This review evaluates the potential strengths and weaknesses of DNP-enhanced (13)C magnetic resonance spectroscopic imaging (DNP-MRSI) as a clinical imaging technique in comparison to PET. The major advantage of ...

The strong signal enhancement attainable by hyperpolarization methods has allowed the detection of heteronuclei in magnetic resonance imaging (MRI), allowing to obtain high quality images with very high signal to noise ratios in few seconds. The four methods to produce hyperpolarized molecules, i.e. the "brute force" approach, optical pumping of noble ...

Significant 13C NMR signal enhancement by a factor of 5000 of a barbituric acid derivative (5-methyl-5-propenyl-barbituric acid) via parahydrogen induced polarization is presented. This hyperpolarization is achieved by hydrogenating 5-methyl-5-propargyl-barbituric acid with 98% enriched para-H2 under elevated temperature and pressure ...

Significant (13)C NMR signal enhancement by a factor of 5000 of a barbituric acid derivative (5-methyl-5-propenyl-barbituric acid) via parahydrogen induced polarization is presented. This hyperpolarization is achieved by hydrogenating 5-methyl-5-propargyl-barbituric acid with 98% enriched para-H(2) under elevated temperature and ...

Hyperpolarized technology utilizing dynamic nuclear polarization has enabled rapid and high-sensitivity measurements of (13)C metabolism in vivo. The most commonly used in vivo agent for hyperpolarized (13)C metabolic imaging thus far has been [1-(13)C]pyruvate. In ...

Dynamic nuclear polarization can create hyperpolarized compounds with MR signal-to-noise ratio enhancements on the order of 10,000-fold. Both exogenous and normally occurring endogenous compounds can be polarized, and their initial concentration and downstream metabolic products can be assessed using MR spectroscopy. Given the transient nature of the ...

Imaging exams involving hyperpolarized, (13)C-labeled compounds require novel RF coils for efficient signal utilization. While (13)C coils are required for mapping the spatial distribution of the hyperpolarized compounds, imaging/pulsing at different frequencies is also ...

Hyperpolarization of nuclear spins through techniques such as dynamic nuclear polarization (DNP) can greatly increase the signal-to-noise ratio in NMR measurements, thus eliminating the need for signal averaging. This enables the study of many dynamic processes which would otherwise not be amenable to study by NMR spectroscopy. A report of solid- to liquid-state DNP of a short ...

MR techniques using hyperpolarized (13) C have successfully produced examples of angiography and intermediary metabolic imaging, but, to date, no receptor imaging has been attempted. The goal of this study was to synthesize and evaluate a novel hyperpolarizable molecule, 2,2,3,3-tetrafluoropropyl 1-(13) ...

Choline as a reporter molecule has been investigated by in vivo magnetic resonance for almost three decades. Accumulation of choline metabolites (mainly the phosphorylated forms) had been observed in malignancy in preclinical models, ex-vivo, in vivo and in patients. The combined choline metabolite signal appears in (1) H-MRS of the brain and its relative intensity had been used as a diagnostic ...

pH is a fundamental physiological parameter that is tightly controlled by endogenous buffers. The acid-base balance is altered in many disease states, such as inflammation, ischemia and cancer. Despite the importance of pH, there are currently no routine methods for imaging the spatial distribution of pH in humans. The enormous gain in sensitivity afforded by dynamic nuclear polarization (DNP) has ...

Application of 13C MRS in vivo on whole body MR system has been limited due to the low static field (and consequent low signal to noise ratio�SNR) of these scanners; thus there have been few reports of 1H decoupled 13C MRS in vivo using a clinical MR platform. The recent development of techniques to retain highly polarized spins in solution following DNP ...

Dynamic nuclear polarization is an emerging technique for increasing the sensitivity of magnetic resonance imaging and spectroscopy, particularly for low-? nuclei. The technique has been applied recently to a number of (13) C-labeled cell metabolites in biological systems: the increase in signal-to-noise allows the spatial distribution of an injected ...

Gadolinium contrast agents are known to affect the outer-sphere relaxivities of nuclei other than protons. We have investigated the heteronuclear relaxivities of four commercial gadolinium contrast agents (Magnevist, Omniscan, Dotarem and Gadovist) on the relaxation of (13)C in glycine, (13)C in pyruvate and (15)N in choline with long relaxation times. ...

Hyperpolarization is the general term for a method of enhancing the spin-polarization difference of populations of nuclei in a magnetic field. No less than 5 distinct techniques (dynamic nuclear polarization [DNP]; parahydrogen-induced polarization-parahydrogen and synthesis allow dramatically enhanced nuclear alignment [PHIP-PASADENA]; xenon/helium polarization transfer; ...

[1-(13)C]pyruvate is a readily polarizable substrate that has been the subject of numerous magnetic resonance spectroscopy (MRS) studies of in vivo metabolism. In this work (13)C-MRS of hyperpolarized [1-(13)C]pyruvate was used to interrogate a ...

Intermolecular dipolar interactions between proton and carbon spins can be used to indirectly detect carbon spectra with high sensitivity. In this communication, we present a modified sequence that, in addition to the high sensitivity of heteronuclear intermolecular multiple quantum coherence (iMQC) experiments, retains the line narrowing capability characteristic of homonuclear zero-quantum ...

Intermolecular dipolar interactions between proton and carbon spins can be used to indirectly detect carbon spectra with high sensitivity. In this communication, we present a modified sequence that, in addition to the high sensitivity of heteronuclear intermolecular multiple quantum coherence (iMQC) experiments, retains the line narrowing capability characteristic of homonuclear zero-quantum ...

We show here that hyperpolarized [1-(13)C]pyruvate can be used to detect treatment response in a glioma tumor model; a tumor type where detection of response with (18)fluoro-2-deoxyglucose, using positron emission tomography, is limited by the high background signals from normal brain tissue. ...

Choline as a reporter molecule has been investigated by in vivo magnetic resonance for almost three decades. Accumulation of choline metabolites (mainly the phosphorylated forms) had been observed in malignancy in preclinical models, ex-vivo, in vivo and in patients. The combined choline metabolite signal appears in (1)H-MRS of the brain and its relative intensity had been used as a diagnostic ...

Hyperpolarization of spins via dynamic nuclear polarization (DNP) has been explored as a method to non-invasively study real-time metabolic processes occurring in vivo using (13)C-labeled substrates. Recently, hyperpolarized (13)C pyruvate has been used to characterize in ...

Hyperpolarization of (13) C labeled substrates via dynamic nuclear polarization has been used as a method to noninvasively study real-time metabolic processes occurring in vivo. In these studies, proper calibration of radiofrequency transmit power is required to efficiently observe rapidly decaying magnetization. Conventional transmit ...

Fast chemical shift imaging (CSI) techniques are advantageous in metabolic imaging of hyperpolarized compounds due to the limited duration of the signal amplification. At the same time, reducing the acquisition time in hyperpolarized imaging does not necessarily lead to the conventional penalty in signal-to-noise ratio that occurs in imaging at thermal ...

Fast chemical shift imaging (CSI) techniques are advantageous in metabolic imaging of hyperpolarized compounds due to the limited duration of the signal amplification. At the same time, reducing the acquisition time in hyperpolarized imaging does not necessarily lead to the conventional penalty in signal-to-noise ratio that occurs in imaging at thermal ...

A fast spiral chemical shift imaging (CSI) has been developed to address the challenge of the limited acquisition window in hyperpolarized 13C metabolic imaging. The sequence exploits the sparsity of the spectra and prior knowledge of resonance frequencies to reduce the measurement time by undersampling the data in the spectral domain. ...

Dynamic nuclear polarization (DNP) of (13)C-labeled metabolic substrates in vitro and their subsequent intravenous administration allow both the location of the hyperpolarized substrate and the dynamics of its subsequent conversion into other metabolic products to be detected in vivo. We report here the hyperpolarization of [1-(13)C]-ascorbic acid (AA) and ...

PURPOSEThe goal of this work was to develop a fast 3D chemical shift imaging technique for the non-invasive measurement of hyperpolarized ¹³C-labeled substrates and metabolic products at low concentration.MATERIALS AND METHODSMultiple echo 3D balanced steady state MR imaging (ME-3DbSSFP) was performed in vitro on a syringe containing ...

Undersampled spiral CSI (spCSI) using a free induction decay (FID) acquisition allows sub-second metabolic imaging of hyperpolarized 13C. Phase correction of the FID acquisition can be difficult, especially with contributions from aliased out-of-phase peaks. This work extends the spCSI sequence by incorporating double spin echo ...

In this manuscript, the remarkable NMR signal enhancement that can be provided by dynamic nuclear polarization (DNP) was combined with the reactivity of acetic anhydride with amines to perform rapid, high SNR analyses of amino acid mixtures and to hyperpolarize new biomolecules of interest. [1,1-(13)C] acetic anhydride is an excellent ...

In order to compare in vivo metabolism between malignant gliomas and normal brain, (13)C magnetic resonance (MR) spectroscopic imaging data were acquired from rats with human glioblastoma xenografts (U-251 MG and U-87 MG) and normal rats, following injection of hyperpolarized ...

Dynamic nuclear polarization and dissolution offer the exciting possibility of imaging biochemical reactions in vivo, including some of the key enzymatic reactions involved in cellular metabolism. The development of new pulse sequence strategies has been motivated by demanding applications, such as the imaging of hyperpolarized metabolite distributions in the heart. In this ...

Measurements of the kinetics of hyperpolarized (13)C label exchange between [1-(13)C]pyruvate and lactate in suspensions of intact and lysed murine lymphoma cells, and in cells in which lactate dehydrogenase expression had been modulated by inhibition of the PI3K pathway, were used to determine ...

With signal-to-noise ratio enhancements on the order of 10,000-fold, hyperpolarized MRSI of metabolically active substrates allows the study of both the injected substrate and downstream metabolic products in vivo. Although hyperpolarized [1-(13) C]pyruvate, in particular, has been used to demonstrate metabolic ...

In the last 25?years, (13) ?C MRS has been established as the only noninvasive method for the measurement of glutamate neurotransmission and cell-specific neuroenergetics. Although technically and experimentally challenging, (13) ?C MRS has already provided important new information on the relationship between ...

By infusing [1-13C] acetate intravenously for 60 minutes before patient enters MR, glial metabolic rate was determined during 25.6 minute-13C acquisition (SAGA, above). 13C MRS spectra (154-164ppm) acquired from frontal brain (inset) showing enrichment of bicarbonate ...

(13) C MR spectroscopy studies performed on hearts ex vivo and in vivo following perfusion of prepolarized [1-(13) C]pyruvate have shown that changes in pyruvate dehydrogenase (PDH) flux may be monitored non-invasively. However, to allow investigation of Krebs cycle metabolism, the (13) ...

To investigate metabolic exchange between 13C1-pyruvate, 13C1-lactate, and 13C1-alanine in pre-clinical model systems using kinetic modeling of dynamic hyperpolarized 13C spectroscopic data and to examine the relationship between fitted parameters and ...

This study investigated the application of an acquisition that selectively excites the [1-13C]lactate resonance and allows dynamic tracking of the conversion of 13C-lactate from hyperpolarized 13C-pyruvate at a high spatial resolution. In order to characterize metabolic processes occurring in a mouse model of prostate cancer, 20 ...

Pyruvate is included in the energy production of the heart muscle and is metabolized into lactate, alanine, and CO(2) in equilibrium with HCO(3) (-). The aim of this study was to evaluate the feasibility of using (13)C hyperpolarization enhanced MRI to monitor pyruvate metabolism in the heart during an ischemic episode. The left ...

Magnetic Resonance Imaging (MRI) is one of the most powerful non-invasive techniques in medical diagnostics that provides spatial and functional information. The sensitivity of NMR, imaging or spectroscopy, is strongly limited by the low Boltzmann polarization that can be reached at room temperature and any achievable field strength. A way out is the use of the Dynamic Nuclear Polarization (DNP) ...

[1-(13)C] pyruvate pre-polarized via DNP has been used in animal models to probe changes in metabolic enzyme activities in vivo. To more accurately assess the metabolic state and its change from disease progression or therapy in a specific region or tissue in vivo, it may be desirable to separate the downstream ...

[1-13C] pyruvate pre-polarized via DNP has been used in animal models to probe changes in metabolic enzyme activities in vivo. To more accurately assess the metabolic state and its change from disease progression or therapy in a specific region or tissue in vivo, it may be desirable to separate the downstream 13C ...

We use the PASADENA (parahydrogen and synthesis allow dramatically enhanced nuclear alignment) method to achieve 13C polarization of approximately 20% in seconds in 1-13C-succinic-d2 acid. The high-field 13C multiplets are observed as a function of pH, and the line broadening of C1 is pronounced in the region of ...

The combination of ex situ dynamic nuclear polarization (DNP) with nuclear magnetic resonance (NMR) leads to signal-to-noise enhancements of 10(3)-10(4) compared to conventional NMR. Ex situ DNP, however, is ill-suited for collecting the array of transients needed in 2D NMR spectroscopy. Spatially encoded single-scan 2D NMR methods can circumvent this drawback, yet these "ultrafast" experiments ...

We report metabolic images of 13C, following injection of a bolus of hyperpolarized [1-13C] pyruvate in a live rat. The data were acquired on a clinical scanner, using custom coils for volume transmission and array reception. Proton blocking of all carbon resonators enabled proton anatomic imaging with the system body coil, to allow ...

Methods for the simultaneous polarization of multiple 13C-enriched metabolites were developed to probe several enzymatic pathways and other physiologic properties in vivo, using a single intravenous bolus. A new method for polarization of 13C sodium bicarbonate suitable for use in patients was developed, and the co-polarization of 13C sodium bicarbonate ...

Methods for the simultaneous polarization of multiple 13C-enriched metabolites were developed to probe several enzymatic pathways and other physiologic properties in vivo, using a single intravenous bolus. A new method for polarization of 13C sodium bicarbonate suitable for use in patients was developed, and the co-polarization of 13C sodium bicarbonate ...

Contrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized (13) C labeled 2-methylpropan-2-ol (also known as dimethylethanol, tertiary butyl alcohol and tert-butanol) as a freely diffusible ...

Real-time in vivo measurements of metabolites are performed by signal enhancement of [1-(13) C]pyruvate using dynamic nuclear polarization, rapid dissolution and intravenous injection, acquisition of free induction decay signals and subsequent quantification of spectra. The commonly injected dose of hyperpolarized pyruvate is larger ...

Dynamic nuclear polarization (DNP) has proved to be one of the most effective methods to increase the nuclear spin polarization in inorganic as well as organic materials since several decades. In combination with methods to rapidly dissolve the polarized solid sample it is possible to obtain a solution of molecules containing hyperpolarized nuclei. This has enabled new ...

Coincidence detection at the nucleus laminaris (NL) of a chicken was improved between embryos (embryonic days (E) 16 and 17) and chicks (post-hatch days (P) 2-7) in slice preparations. Electrical stimuli were applied bilaterally to the projection fibres to the NL at various intervals. The response window corresponding to the temporal separation of electrical stimuli that resulted in half-maximal ...

We have been developing a polarized HD target for particle physics at the SPring-8 under the leadership of the RCNP, Osaka University for the past 5 years. Nuclear polarizaton is created by means of the brute force method which uses a high magnetic field (~17 T) and a low temperature (~ 10 mK). As one of the promising applications of the brute force method to life sciences we started a new ...

[1-13C]pyruvate is readily polarizable substrate that has been the subject of numerous magnetic resonance spectroscopy (MRS) studies of in vivo metabolism. In this work, ¹³C-MRS of hyperpolarized [1-¹³C]pyruvate is used to interrogate a metabolic pathway involved in neither aerobic nor ...

Hyperpolarized ¹³C MRSI can detect not only the uptake of the pre-polarized molecule but also its metabolic products in vivo, thus providing a powerful new method to study cellular metabolism. Imaging the dynamic perfusion and conversion of these metabolites provides additional tissue information but requires methods for efficient ...

... Accession Number : ADA021229. Title : Spontaneous and Induced Membrane Hyperpolarizations in Macrophages,. Corporate ...

NMR spectroscopy is an established, versatile technique for the detection of molecular interactions, even when these interactions are weak. Signal enhancement by several orders of magnitude through dynamic nuclear polarization alleviates several practical limitations of NMR-based interaction studies. This enhanced non-equilibrium polarization contributes sensitivity for the detection of molecular ...

A set of molecules in which a glucose moiety is bound to a hydrogenable synthon has been synthesized and evaluated for hydrogenation reactions and for the corresponding para-hydrogen-induced polarization (PHIP) effects, in order to select suitable candidates for an in vivo magnetic resonance imaging (MRI) method for the assessment of glucose cellular uptake. It has been found that amidic ...

The application of hyperpolarization techniques for MRI purposes is gathering increasing attention, especially for nuclei such as (13)C or (129)Xe. Among the different proposed methods, ParaHydrogen Induced Polarization requires relatively cheap equipment. The setup of an MRI experiment by means of parahydrogen requires the application of skills and methodologies that derive ...

The application of hyperpolarization techniques for MRI purposes is gathering increasing attention, especially for nuclei such as (13)C or (129)Xe. Among the different proposed methods, ParaHydrogen Induced Polarization requires relatively cheap equipment. The setup of an MRI experiment by means of parahydrogen requires the application of skills and methodologies that derive ...

Injection of hyperpolarized (13)C-labelled pyruvate ((13)C pyruvate) is under evaluation as an agent for medical metabolic imaging by measuring formation of (13)C lactate using magnetic resonance spectroscopy of the (13)C nuclei. A quantitative method for analysis of these (13)C-labelled ...

A 2 MeV proton tandem accelerator with vacuum insulation was developed and first experiments are carried out in the Budker Institute of Nuclear Physics (Novosibirsk). The accelerator is designed for neutron production via reaction (7)Li(p,n)(7)Be for the boron neutron-capture therapy of the brain tumors, and for explosive detection based on 9.1724 MeV ...

A 2 MeV proton tandem accelerator with vacuum insulation was developed and first experiments are carried out in the Budker Institute of Nuclear Physics (Novosibirsk). The accelerator is designed for neutron production via reaction 7Li(p,n)7Be for the boron neutron-capture therapy of the brain tumors, and for explosive detection based on 9.1724 MeV ...

Dark voltage and light responses of isolated retinal rods of Rana esculenta were investigated by employing the whole-cell patch-clamp technique. When the recording pipette was filled with a medium devoid of nucleotides, a spontaneous hyperpolarization of the dark voltage partly due to a diffusional loss of cGMP and its precursor GTP and a retardation in the recovery of the ...

Purpose: To develop a dynamic magnetic resonance imaging (MRI) tagging technique using hyperpolarized helium-3 (HP He-3) to track lung motion. Methods and Materials: An accelerated non-Cartesian k-space trajectory was used to gain acquisition speed, at the cost of introducing image artifacts, providing a viable strategy for obtaining whole-lung coverage ...

The pteropod mollusk, Clione limacina, exhibits behaviorally relevant swim speed changes that occur within the context of the animal's ecology. Modulation of C. limacina swimming speed involves changes that occur at the network and cellular levels. Intracellular recordings from interneurons of the swim central pattern generator show the presence of a sag potential that is indicative of the ...

Recently it has been reported that "I(f) channel blockers", which block the hyperpolarization-activated inward current (I(f)) in heart sino atrial node cells, also block the hyperpolarization-activated inward current (I(h)) in other tissues. Here we compared the effects of one of these agents, ZD7288 [4-(N-ethyl-N-phenylamino)-1, 2-dimethyl-6-(methylamino) ...

Oxygen isotopes and Mg/Ca ratios in long-lived coralline algae record ambient seawater temperature in their calcified tissues over time. Similarly, carbon stable isotopes (?13C) in the calcified tissue may record ?13C values of ambient seawater dissolved inorganic carbon. Here, we measured ...

The /sup 13/C-AP breath test is shown to be a convenient, noninvasive method to monitor velocity and capacity of P450-dependent AP N-demethylation in infancy and childhood. According to /sup 13/C-AP breath tests, neonates have a very low capacity to eliminate /sup 13/CO/sub 2/, which is only 15 to 21% of the ...

In the last decade, there has been a resurgence of interest in the use of stable isotopes of carbon, oxygen, and nitrogen in the life sciences and medicine fueled by the increased availability of the isotopes and isotopically labeled compounds and of instruments for their detection. Accelerated development of /sup 13/C, /sup 15/N, and ...

Hyperpolarization greatly enhances opportunities to observe in vivo metabolic processes in real time. Accessible timescales are, however, limited by nuclear spin relaxation times, and sensitivity is limited by magnetogyric ratios of observed nuclei. The majority of applications to date have involved direct (13)C observation of ...

Even at this early stage of development, it is clear that the imaging of hyperpolarized (13) C-enriched molecules and their metabolic products offers a new approach to the study of the physiology and disease of the heart. The technology is practical in humans and, for this reason, we consider whether a role in clinical decision-making ...

The combination of 2D 1H-13C and 1H-29Si solid state NMR, hyperpolarized 129Xe NMR, synchrotron X-ray diffraction, together with adsorption measurements of vapors and gases for environmental and energetic relevance, was used to investigate the structure and the properties of periodic mesoporous hybrid p-phenylenesilica endowed with ...

Glioblastoma (GBM) is the most common and lethal primary malignant brain tumor in humans. Because the phosphatidylinositol-3-kinase (PI3K) signaling pathway is activated in more than 88% of GBM, new drugs which target this pathway, such as the mTOR inhibitor Everolimus, are currently in clinical trials. Early tumor response to molecularly targeted treatments remains challenging to assess ...

sample was analyzed by 13 C-NMR.to melamine�formaldehyde,12 melamine�urea�for- maldehyde,14 phenol equation f � km/aE and connected regression equations which have al-resorcinol�formaldehyde (RF), melamine

Nitrate esters on the C sub 2 , C sub 3 , and C sub 6 positions of the anhydroglucose units of cellulose nitrate (NC) can be distinguished using high resolution Fourier transform nuclear magnetic measurements of sup 13 C. Changes in the ester population a...

... performed preliminary experiments which demonstrated that hyperpolarized 129Xe spectroscopy may be useful in the diagnosis of atherosclerosis. ...

New ?13C data are presented from ten coral skeletons collected from Florida and the Caribbean. These corals range from 96 to 200 years in age and were collected between 1976 and 2002. The change in the ?13C of the skeletons (??13C/?t) of these corals has been measured between 1900 and 1990 and have been compared ...

Carbon-13 NMR has traditionally been a method of choice for the determination of metabolic pathways. Through fractional labeling, (13) C spectra allow the identification of fragments incorporated as a unit into a biosynthesized molecule. The low sensitivity of (13) C spectroscopy is an impediment to such studies, ...

The morphology and molecular mobility changes of the side chains for hard alpha-keratin due to oxidative and reductive/oxidative treatments for temperatures around the DSC denaturation peak were investigated by (1)H, (13)C, and (129)Xe NMR spectroscopy and (1)H spin diffusion. Proton wide-line spectra were used to obtain the phase composition (rigid, ...

High polarization of nuclear spins in liquid state through hyperpolarized technology utilizing dynamic nuclear polarization has enabled the direct monitoring of ¹³C metabolites in vivo at a high signal-to-noise ratio. Acquisition time limitations due to T₁ decay of the hyperpolarized signal require ...

1. Hyperpolarization-activated Cl- currents (ICl,hyp) were investigated in the T84 human adenocarcinoma cell line, using the patch-clamp whole-cell configuration. 2. During whole-cell recording with high-chloride and ATP-containing internal solutions, hyperpolarizing jumps from a holding potential of 0 mV elicited slow inward current relaxations, carried ...

Rationale:The hyperpolarization-activated current I(h) that is generated by hyperpolarization-activated cyclic nucleotide-gated channels (HCNs) plays a key role in the control of pacemaker activity in sinoatrial node cells of the heart. By contrast, it is unclear whether I(h) is also relevant for normal function of cardiac ventricles.Objective:To study the ...

Elastic and inelastic electron scattering measurements on /sup 13/C and /sup 14/N have been performed at the Bates Linear Accelerator. The measurements of the elastic M1, 3.088 MeV E1, and 9.50 MeV M4 form factors of /sup 13/C span the momentum transfer range of 3.5 to 4.6 fm/sup -1/. The ...

... Abstract : A method of preparing the title compound from methyl-13C iodide through acetophenone-2-13C, 1-phenylethanol-2-13C, styrene-2-13C ...

SCAssign (side-chain assignment) is a Sparky extension written in Python to assist the NMR resonance assignment of aliphatic side-chains of uniformly (13)C,(15)N-labeled large proteins. It is based on a general strategy recently developed in our laboratory that makes use of 4D (13)C,(15)N-edited NOESY, 3D ...

Several experimental examples are discussed to illustrate that single-particle molecular orbital behavior has become an established reality in nuclear physics over the last several years. Measurements and analyses of inelastic scattering in the /sup 13/C + /sup 12/C and /sup 17/O + /sup 12/C systems, and of neutron transfer in the /sup ...

In the direct pyrolysis of wood (Juniperus monosperma) in vacuo, charcoal yields between 25% and 40% were obtained at temperatures of greater than 300 degrees C in runs of 35 minutes, and /sup 13/C fractionation as determined from the difference between the delta/sup 13/C of the wood and charcoal amounted to ...

In recent years methods of creating 'hyperpolarized' substances have gained considerable attention in biomedical magnetic resonance and dynamic nuclear polarization (DNP) is one of the most promising, especially for imaging applications. Here we present results of DNP studies on protons and 13C nuclei in frozen solutions of sodium acetate and glycine, dissolved in ...

We describe the details of the magnetic resonance spectroscopy and chemical shift imaging techniques for the human brain which have been developed over the last two decades. With these non-invasive tools, it is now readily possible to repeatedly assay up to 20 common brain metabolites. From the perspective of drug discovery, each of these metabolites could fulfill a number of useful functions: ...

Commercial MR imaging/magnetic resonance spectroscopic imaging (MRSI) packages for staging prostate cancer on 1.5-T MR scanners are now available. The technology is becoming mature enough to begin assessing its clinical utility in selecting, planning, and following prostate cancer therapy. Before therapy, 1.5-T MR imaging/MRSI has the potential to improve the local evaluation of prostate cancer ...

1. Benidipine (KW-3049), a new derivative of 1,4-dihydropyridine (DHP), showed dose-dependent inhibition of Ca current (ICa) which was elicited by depolarization from -40 mV to +10 mV at 0.2 Hz in single cardiac cells isolated from guinea-pig ventricle under whole cell voltage clamp. Half inhibition doses (IC50) of benidipine and nifedipine for the peak ICa at +10 mV were 2.7 nM and 63.1 nM, ...

Parallel imaging presents a promising approach for MRI of hyperpolarized nuclei, as the penalty in signal-to-noise ratio typically encountered with (1) H MRI due to a reduction in acquisition time can be offset by an increase in flip angle. The signal-to-noise ratio of hyperpolarized MRI generally exhibits a strong dependence on flip angle, which makes a ...

The oxygen isotopic composition and Mg/Ca ratios in the skeletons of long-lived coralline algae record ambient seawater temperature over time. Similarly, the carbon isotopic composition in the skeletons record ?13C values of ambient seawater dissolved inorganic carbon. Here, we measured ?13C in the coralline alga ...

Pancreatic and venom phospholipase A/sub 2/ display a marked preference for micellar substrates and act poorly on monomeric substrates. The authors have now examined the merit of the proposal that the product-release step is slow, but is accelerated when the enzyme acts on aggregated phospholipids. Measurements of H/sub 2/ /sup 18/O isotope exchange into specifically-labeled ...

Ovarian follicles of Hyalophora cecropia are shown here to undergo a comprehensive transformation about 2 days after they are first formed and several hours before the first yolk spheres are visible. (1) Electrical coupling initiates between the follicle cells and the oocyte-nurse cell complex, as well as between adjacent follicles. (2) Oocyte and nurse cell membranes begin to ...

Mechanoelectric feedback in heart and smooth muscle is thought to depend on diverse channels that afford myocytes a mechanosensitive cation conductance. Voltage-gated channels (e.g., Kv1) are stretch sensitive, but the only voltage-gated channels that are cation permeant, the pacemaker or HCN (hyperpolarization-activated cyclic nucleotide-gated) channels, have not been tested. ...

Hierarchically ordered positive and negative replicas of wood cellular structures prepared using surfactant templating methods under acidic and basic conditions have been studied by means of continuous flow hyperpolarized 129Xe NMR, solid-state MAS 13C, 29Si, and 2D WISE NMR spectroscopic techniques. 129Xe NMR data confirm a highly ...

The Deepwater Horizon oil spill was unprecedented in total loading of petroleum hydrocarbons accidentally released to a marine ecosystem. Controversial application of chemical dispersants presumably accelerated microbial consumption of oil components, especially in warm Gulf of Mexico surface waters. We employed ?13C as a tracer of ...

The authors report high-sensitivity emission profiles from the J = 0--1 transitions of (/sup 12/C/sup 16/O) and (/sup 13/C/sup 16/O) towards IRC+10216. It appears that the spherically symmetric uniform mass-outflow model proposed by Morris (1975) is necessary to describe the line profiles. The outflow appears to be slightly ...

High-sensitivity emission profiles from the J=0reverse arrow1 transitions of /sup 12/C/sup 16/O and /sup 13/C/sup 16/O have been observed toward IRC+10216. It appears that the spherically symmetric uniform mass-outflow model proposed by Morris (1975) is necessary to describe the line profiles. The outflow appears to be slightly ...

Continuous-flow hyperpolarized xenon-129 NMR is used to characterize gas exchange and diffusion in two types of polycrystalline solids with one-dimensional channels. Expressions for the hyperpolarized NMR selective-saturation recovery signal are derived for normal and single-file diffusion.

Cellular/Molecular Adenosine-Evoked Hyperpolarization of Retinal Ganglion Cells Is Mediated by G, Minnesota 55455 Adenosine is a neuromodulator that activates presynaptic receptors to regulate synaptic transmission and postsynaptic receptors to hyperpolarize neurons. Here, we report that adenosine

We present an optimized method for compound-specific stable carbon isotope (delta(13)C) analysis of n-alkanes. For sample preparation, the traditionally used Soxhlet extraction was replaced by accelerated solvent extraction (ASE). delta(13)C values of individual n-alkanes--measured using gas ...

Hyperpolarization-activated cyclic nucleotide modulated current (I(h)) sets resonance frequency within the ?-range (5�12 Hz) in pyramidal neurons. However, its precise contribution to the temporal fidelity of spike generation in response to stimulation of excitatory or inhibitory synapses remains unclear. In conditions where pharmacological blockade of I(h) does not affect ...

The role of K⁺ channels and membrane potential in myoblast fusion was evaluated by examining resting membrane potential and timing of expression of K⁺ currents at three stages of differentiation of human myogenic cells: undifferentiated myoblasts, fusion-competent myoblasts (FCMBs), and freshly formed myotubes.Two K⁺ currents ...

We have previously reported an important role of increased tyrosine phosphorylation activity by Src in the modulation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. Here we provide evidence showing a novel mechanism of decreased tyrosine phosphorylation on HCN channel properties. We found that the receptor-like protein-tyrosine phosphatase-alpha ...

We have previously reported an important role of increased tyrosine phosphorylation activity by Src in the modulation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. Here we provide evidence showing a novel mechanism of decreased tyrosine phosphorylation on HCN channel properties. We found that the receptor-like protein-tyrosine phosphatase-? ...

1. The intrinsic response properties of turtle Purkinje cells and the underlying conductances have been investigated with intradendritic and intrasomatic recordings in a slice preparation. 2. The active generation site for fast Na+ spikes was confined to the soma and for slow Ca2+ spikes to the dendrites. The configuration and generation of Ca2+ spikes was more affected by the level of ...

1. A polarization-induced membrane current, IQ, was investigated in the slowly adapting lobster stretch receptor neurone using conventional electrophysiological techniques including intracellular ion measurements. 2. The current was readily blocked by Cs+ in a voltage-dependent manner, but proved to be unaffected by tetrodotoxin, tetraethylammonium and 4-aminopyridine. 3. From an analysis of the ...

... 6.1775 Progesterone Induces Hyperpolarization after a Transient Depolarization Phase in Human Spermatozoa1C. Patrat2, C. Serres,...

... doi: 10.1562/2005-05-23-RA-537 Photosensitive Signal Transduction Induces Membrane Hyperpolarization in Paramecium bursariaAtsus...

In hyperpolarized (HP) noble-gas magnetic resonance imaging, large nuclear spin polarizations, about

The viability of the new technique of hyperpolarized (129)Xe MRI (HypX-MRI) for imaging organs other