Exploring contrast-enhancing staining agents for studying adipose tissue through contrast-enhanced computed tomography.

Contrast-enhanced computed tomography offers a nondestructive approach to studying adipose tissue in 3D. Several contrast-enhancing staining agents (CESAs) have been explored, whereof osmium tetroxide (OsO4) is the most popular nowadays. However, due to the toxicity and volatility of the conventional OsO4, alternative CESAs with similar staining properties were desired. Hf-WD 1:2 POM and Hexabrix have proven effective for structural analysis of adipocytes using contrast-enhanced computed tomography but fail to provide chemical information. This study introduces isotonic Lugol's iodine (IL) as an alternative CESA for adipose tissue analysis, comparing its staining potential with Hf-WD 1:2 POM and Hexabrix in murine caudal vertebrae and bovine muscle tissue strips. Single and sequential staining protocols were compared to assess the maximization of information extraction from each sample. The study investigated interactions, distribution, and reactivity of iodine species towards biomolecules using simplified model systems and assesses the potential of the CESA to provide chemical information. (Bio)chemical analyses on whole tissues revealed that differences in adipocyte gray values post-IL staining were associated with chemical distinctions between bovine muscle tissue and murine caudal vertebrae. More specific, a difference in the degree of unsaturation of fatty acids was identified as a likely contributor, though not the sole determinant of gray value differences. This research sheds light on the potential of IL as a CESA, offering both structural and chemical insights into adipose tissue composition.

Benchtop In Situ Measurement of Full Adsorption Isotherms by NMR.

Physisorption using gas or vapor probe molecules is the most common characterization technique for porous materials. The method provides textural information on the adsorbent as well as the affinity for a specific adsorbate, typically through equilibrium pressure measurements. Here, we demonstrate how low-field NMR can be used to measure full adsorption isotherms, and how by selectively measuring 1H spins of the adsorbed probe molecules, rather than those in the vapor phase, this "NMR-relaxorption" technique provides insights about local dynamics beyond what can be learned from physisorption alone. The potential of this double-barreled approach was illustrated for a set of microporous metal-organic frameworks (MOFs). For methanol adsorption in ZIF-8, the method identifies multiple guest molecules populations assigned to MeOH clusters in the pore center, MeOH bound at cage windows and to MeOH adsorption on defect sites. For UiO-66(Zr), the sequential pore filling is demonstrated and accurate pore topologies are directly obtained, and for MIL-53(Al), structural phase transitions are accurately detected and linked with two populations of dimeric chemical species localized to specific positions in the framework.

A Cooperative OSDA Blueprint for Highly Siliceous Faujasite Zeolite Catalysts with Enhanced Acidity Accessibility.

A cooperative OSDA strategy is demonstrated, leading to novel high-silica FAU zeolites with a large potential for disruptive acid catalysis. In bottom-up synthesis, the symbiosis of choline ion (Ch+ ) and 15-crown-5 (CE) was evidenced, in a form of full occupation of the sodalite (sod) cages with the trans Ch+ conformer, induced by the CE presence. CE itself occupied the supercages along with additional gauche Ch+ , but in synthesis without CE, no trans was found. The cooperation, and thus the fraction of trans Ch+ , was closely related to the Si/Al ratio, a key measure for FAU stability and acidity. As such, a bottom-up handle for lowering the Al-content of FAU and tuning its acid site distribution is shown. A mechanistic study demonstrated that forming sod cages with trans Ch+ is key to the nucleation of high-silica FAU zeolites. The materials showed superior performances to commercial FAU zeolites and those synthesized without cooperation, in the catalytic degradation of polyethylene.

Topochemical Engineering of Cellulose-Carboxymethyl Cellulose Beads: A Low-Field NMR Relaxometry Study.

The demand for more ecological, highly engineered hydrogel beads is driven by a multitude of applications such as enzyme immobilization, tissue engineering and superabsorbent materials. Despite great interest in hydrogel fabrication and utilization, the interaction of hydrogels with water is not fully understood. In this work, NMR relaxometry experiments were performed to study bead-water interactions, by probing the changes in bead morphology and surface energy resulting from the incorporation of carboxymethyl cellulose (CMC) into a cellulose matrix. The results show that CMC improves the swelling capacity of the beads, from 1.99 to 17.49, for pure cellulose beads and beads prepared with 30% CMC, respectively. Changes in water mobility and interaction energy were evaluated by NMR relaxometry. Our findings indicate a 2-fold effect arising from the CMC incorporation: bead/water interactions were enhanced by the addition of CMC, with minor additions having a greater effect on the surface energy parameter. At the same time, bead swelling was recorded, leading to a reduction in surface-bound water, enhancing water mobility inside the hydrogels. These findings suggest that topochemical engineering by adjusting the carboxymethyl cellulose content allows the tuning of water mobility and porosity in hybrid beads and potentially opens up new areas of application for this biomaterial.

Vapor-Phase Linker Exchange of the Metal-Organic Framework ZIF-8: A Solvent-Free Approach to Post-synthetic Modification.

Zeolitic imidazolate frameworks (ZIFs) are a sub-class of metal-organic frameworks (MOFs). Although generally stable, ZIFs can undergo post-synthetic linker exchange (PSLE) in solution under mild conditions. Herein, we present a novel, solvent-free approach to post-synthetic linker exchange through exposure to linker vapor.

Seasonal adherence to, and effectiveness of, subcutaneous interferon ß-1a administered by RebiSmart® in patients with relapsing multiple sclerosis: results of the 1-year, observational GEPAT-SMART study.

BACKGROUND: Little is known about whether tolerability and adherence to treatment can be influenced by weather and temperature conditions. The objective of this study was to assess monthly and seasonal adherence to and safety of sc IFN-ß1a (Rebif®, Merck) in relapsing-remitting multiple sclerosis (RRMS) patients using the RebiSmart® electronic autoinjector. METHODS: A multicentre, prospective observational study in Greece in adult RRMS patients with EDSS < 6, under Rebif®/RebiSmart® treatment for ≤6 weeks before enrollment. The primary endpoint was monthly, seasonal and annual adherence over 12 months (defined in text). Secondary endpoints included number of relapses, disability, adverse events. RESULTS: Sixty four patients enrolled and 47 completed all study visits (Per Protocol Set - PPS). Mean annual adherence was 97.93% ± 5.704 with no significant monthly or seasonal variations. Mean relapses in the pre- and post- treatment 12-months were 1.1 ± 0.47 and 0.2 ± 0.54 (p < 0.0001, PPS). 10 patients (22%) showed 3-month disability progression, 19 (40%) stabilization and 18 (38%) improvement. EDSS was not correlated to pre- (r = 0.024, p = 0.87) or post-treatment relapses (r = 0.022, p = 0.88). CONCLUSION: High adherence with no significant seasonal or weather variation was observed over 12 months. While the efficacy on relapses was consistent with published studies, we could not identify a relationship between relapses and disability. TRIAL REGISTRATION: Greek registry of non-interventional clinical trials ID: 200136 , date of registration: February 18th, 2013.

High-resolution two-field nuclear magnetic resonance spectroscopy.

Nuclear magnetic resonance (NMR) is a ubiquitous branch of spectroscopy that can explore matter at the scale of an atom. Significant improvements in sensitivity and resolution have been driven by a steady increase of static magnetic field strengths. However, some properties of nuclei may be more favourable at low magnetic fields. For example, transverse relaxation due to chemical shift anisotropy increases sharply at higher magnetic fields leading to line-broadening and inefficient coherence transfers. Here, we present a two-field NMR spectrometer that permits the application of rf-pulses and acquisition of NMR signals in two magnetic centres. Our prototype operates at 14.1 T and 0.33 T. The main features of this system are demonstrated by novel NMR experiments, in particular a proof-of-concept correlation between zero-quantum coherences at low magnetic field and single quantum coherences at high magnetic field, so that high resolution can be achieved in both dimensions, despite a ca. 10 ppm inhomogeneity of the low-field centre. Two-field NMR spectroscopy offers the possibility to circumvent the limits of high magnetic fields, while benefiting from their exceptional sensitivity and resolution. This approach opens new avenues for NMR above 1 GHz.

Sample Shuttling Relaxometry of Contrast Agents: NMRD Profiles above 1 T with a Single Device.

Nuclear magnetic relaxation dispersion (NMRD) profiles are essential tools to evaluate the efficiency and investigate the properties of magnetic compounds used as contrast agents for magnetic resonance imaging (MRI), namely gadolinium chelates and superparamagnetic iron oxide particles. These curves represent the evolution of proton relaxation rates with the magnetic field. NMRD profiles are unparalleled to probe extensively the spectral density function involved in the relaxation of water in the presence of the paramagnetic ion or the magnetic nanoparticles. This makes such profiles an excellent test of the adequacy of a theoretical relaxation model and allow for a predictive approach to the development and optimization of contrast agents. From a practical point of view they also allow to evaluate the efficiency of a contrast agent in a certain range of magnetic fields. Nowadays, these curves are recorded with commercial fast field cycling devices, often limited to a maximum Larmor frequency of 40 MHz (0.94 T). In this article, relaxation data were acquired on a wide range of magnetic fields, from 3.5 × 10-4 to 14 T, for a gadolinium-based contrast agent and for PEGylated iron oxide nanoparticles. We show that the low-field NMRD curves can be completed with high-field data obtained on a shuttle apparatus device using the superconductive magnet of a high-field spectrometer. This allows a better characterization of the contrast agents at relevant magnetic fields for clinical and preclinical MRI, but also refines the experimental data that could be used for the validation of relaxation models.

3D printing of ferromagnetic passive shims for field shaping in magnetic resonance imaging.

Magnetic Resonance Imaging (MRI) often encounters image quality degradation due to magnetic field inhomogeneities. Conventional passive shimming techniques involve the manual placement of discrete magnetic materials, imposing limitations on correcting complex inhomogeneities. To overcome this, we propose a novel 3D printing method utilizing binder jetting technology to enable precise deposition of a continuous range of concentrations of ferromagnetic ink. This approach grants complete control of the magnitude of the magnetic moment within the passive shim enabling tailored corrections of B0 field inhomogeneities. By optimizing the magnetic field distribution using linear programming and an in-house written Computer-Aided Design (CAD) generation software, we printed shims with promising results in generating low spherical harmonic corrections. Experimental evaluations demonstrate feasibility of these 3D printed passive shims to induce target magnetic fields corresponding to second-order spherical harmonic, as evidenced by acquired B0 maps. The electrically insulating properties of the printed shims eliminate the risk of eddy currents and heating, thus ensuring safety. The dimensional fabrication accuracy of the printed shims surpasses previous methods, enabling more precise and localized correction of subject-specific inhomogeneities. The findings highlight the potential of binder-jetted 3D printed passive shims in MRI shimming as a versatile and efficient solution for fabricating passive shims, with the potential to enhance the quality of MRI imaging while also being applicable to other types of Magnetic Resonance systems.

Catalytic tandem dehydrochlorination-hydrogenation of PVC towards valorisation of chlorinated plastic waste.

Chemical treatment of end-of-life PVC at high temperature often results in the formation of polyacetylene and eventually aromatic char. These insoluble conjugated polymers lead to industrial reactor blockages, and limit the efficiency in recycling chlorinated plastic waste. To address this challenge, a solvent-based tandem dehydrochlorination-hydrogenation process is proposed for the conversion of PVC to a saturated polymer backbone. When combining tetrabutylphosphonium ionic liquids and homogeneous Rh catalysts under H2 pressure, 81% dehydrochlorination is reached in 2 h, with the hydrogenation proceeding smoothly with minimal catalyst use of 0.5-2.0 mol% Rh. This process for PVC dechlorination yields soluble products that lack aromatics, have high degrees of dechlorination and possess a tunable content of double bonds. The chemical structures of the partially unsaturated polymer products and of the different structural motifs in the product are accurately monitored by a liquid 1H-NMR method. Finally, X-ray absorption spectroscopy (XAS) sheds light on the catalytic Rh species during the tandem process, which are stabilized by the ionic liquid. This tandem process enables rapid PVC conversion to a saturated organic product, with polyethylene segments giving the opportunity for ensuing recycling steps.

Encapsulation of Cadmium-Free InP/ZnSe/ZnS Quantum Dots in Poly(LMA-co-EGDMA) Microparticles via Co-flow Droplet Microfluidics.

Quantum dots (QDs) are semiconductor nanocrystals that are used in optoelectronic applications. Most modern QDs are based on toxic metals, for example Cd, and do not comply with the European Restriction of Hazardous Substances regulation of the European Union. Latest promising developments focus on safer QD alternatives based on elements from the III-V group. However, the InP-based QDs lack an overall photostability under environmental influences. One design path of achieving stability is through encapsulation in cross-linked polymer matrices with the possibility to covalently link the matrix to surface ligands of modified core-shell QDs. The work focuses on the formation of polymer microbeads suitable for InP-based QD encapsulation, allowing for an individual protection of QDs and an improved processibility via this particle-based approach. For this, a microfluidic based method in the co-flow regime is used that consists of an oil-in-water droplet system in a glass capillary environment. The generated monomer droplets are polymerized in-flow into poly(LMA-co-EGDMA) microparticles with embedded InP/ZnSe/ZnS QDs using a UV initiation. They demonstrate how a successful polymer microparticle formation via droplet microfluidics produces optimized matrix structures leading to a distinct photostability improvement of InP-based QDs compared to nonprotected QDs.

Development of a compact NMR system to measure pO2 in a tissue-engineered graft.

Cellular macroencapsulation devices, known as tissue engineered grafts (TEGs), enable the transplantation of allogeneic cells without the need for life-long systemic immunosuppression. Islet containing TEGs offer promise as a potential functional cure for type 1 diabetes. Previous research has indicated sustained functionality of implanted islets at high density in a TEG requires external supplementary oxygen delivery and an effective tool to monitor TEG oxygen levels. A proven oxygen-measurement approach employs a 19F oxygen probe molecule (a perfluorocarbon) implanted alongside therapeutic cells to enable oxygen- and temperature- dependent NMR relaxometry. Although the approach has proved effective, the clinical translation of 19F oxygen relaxometry for TEG monitoring will be limited by the current inaccessibility and high cost of MRI. Here, we report the development of an affordable, compact, and tabletop 19F NMR relaxometry system for monitoring TEG oxygenation. The system uses a 0.5 T Halbach magnet with a bore diameter (19 cm) capable of accommodating the human arm, a potential site of future TEG implantation. 19F NMR relaxometry was performed while controlling the temperature and oxygenation levels of a TEG using a custom-built perfusion setup. Despite the magnet's nonuniform field, a pulse sequence of broadband adiabatic full-passage pulses enabled accurate 19F longitudinal relaxation rate (R1) measurements in times as short as ∼2 min (R1 vs oxygen partial pressure and temperature (R2 > 0.98)). The estimated sensitivity of R1 to oxygen changes at 0.5 T was 1.62-fold larger than the sensitivity previously reported for 16.4 T. We conclude that TEG oxygenation monitoring with a compact, tabletop 19F NMR relaxometry system appears feasible.

Cardiopulmonary rehabilitation enhances heart rate recovery in patients with COPD.

BACKGROUND: Autonomic dysfunction is present early in the course of COPD, and is associated with adverse outcomes. We utilized heart rate recovery, a simple and validated index of autonomic balance, to investigate the effects of exercise training on autonomic dysfunction in patients with COPD. METHODS: We evaluated 45 stable subjects with COPD who participated in a 36-session exercise-based cardiopulmonary rehabilitation program. Subjects underwent maximal cardiopulmonary exercise testing at baseline and after completion of the rehabilitation program. We recorded exercise testing parameters and heart rate during rest, exercise, and recovery. Heart rate recovery was calculated as heart rate at peak exercise minus heart rate at the first minute of recovery. RESULTS: Thirty-nine subjects (age 66.3 ± 7.8 y, 90% male, body mass index 27.1 ± 4.1 kg/m(2), FEV(1) 45.7 ± 18.7%) completed the program. In these subjects, heart rate recovery increased from 16.2 ± 8.0 beats/min to 18.4 ± 8.4 beats/min (P = .01), resting heart rate decreased from 88.0 ± 10.7 beats/min to 83.3 ± 10.5 beats/min (P = .004), and heart rate at anaerobic threshold decreased from 109.0 ± 12.5 beats/min to 105.5 ± 11.7 beats/min (P = .040). In addition, oxygen consumption (V(O(2))) increased from 14.3 ± 3.7 mL/kg/min to 15.2 ± 3.8 mL/kg/min at peak exercise, and from 9.7 ± 2.4 mL/kg/min to 10.4 ± 2.6 mL/kg/min at anaerobic threshold (both P = .02), while the V(O(2))/t slope increased from -0.32 ± 0.16 mL/kg/min(2) to -0.38 ± 0.19 mL/kg/min(2) (P = .003). Parameters of ventilatory performance improved also. CONCLUSIONS: In subjects with COPD, exercise-based rehabilitation improves heart rate recovery, modestly though, which indicates a degree of attenuated autonomic dysfunction. Exercise and muscular oxidative capacity, as expressed by V(O(2))/t slope, is also improved.

Alteration in molecular structure of alkali activated slag with various water to binder ratios under accelerated carbonation.

Carbonation of alkali activated materials is one of the main deteriorations affecting their durability. However, current understanding of the structural alteration of these materials exposed to an environment inducing carbonation at the nano/micro scale remains limited. This study examined the evolution of phase assemblages of alkali activated slag mortars subjected to accelerated carbonation (1% CO2, 60% relative humidity, up to 28 day carbonation) using XRD, FTIR and 29Si, 27Al, and 23Na MAS NMR. Samples with three water to binder (w/b) ratios (0.35, 0.45, and 0.55) were investigated. The results show that the phase assemblages mainly consisted of C-A-S-H, a disordered remnant aluminosilicate binder, and a minor hydrotalcite as a secondary product. Upon carbonation, calcium carbonate is mainly formed as the vaterite polymorph, while no sodium carbonate is found after carbonation as commonly reported. Sodium acts primarily as a charge balancing ion without producing sodium carbonate as a final carbonation product in the 28-day carbonated materials. The C-A-S-H structure becomes more cross-linked due to the decalcification of this phase as evidenced by the appearance of Q4 groups, which replace the Q1 and Q2 groups as observed in the 29Si MAS NMR spectra, and the dominance of Al(IV) in 27Al MAS NMR. Especially, unlike cementitious materials, the influence of w/b ratio on the crystalline phase formation and structure of C-A-S-H in the alkali activated mortars before and after carbonation is limited.

Does Supramolecular Gelation Require an External Trigger?

The supramolecular gelation of small molecules is typically preceded by an external stimulus to trigger the self-assembly. The need for this trigger stems from the metastable nature of most supramolecular gels and can limit their applicability. Herein, we present a small urea-based molecule that spontaneously forms a stable hydrogel by simple mixing without the addition of an external trigger. Single particle tracking experiments and observations made from scanning electron microscopy indicated that triggerless gelation occurred in a similar fashion as the archetypical heat-triggered gelation. These results could stimulate the search for other supramolecular hydrogels that can be obtained by simple mixing. Furthermore, the mechanism of the heat-triggered supramolecular gelation was elucidated by a combination of molecular dynamics simulations and quantitative NMR experiments. Surprisingly, hydrogelation seemingly occurs via a stepwise self-assembly in which spherical nanoparticles mature into an entangled fibrillary network.

Potential of 1H NMR fingerprinting and a model system approach to study non-enzymatic browning in shelf-stable orange juice during storage.

For the first time, a model system approach was combined with 1H NMR fingerprinting in studying non-enzymatic browning (NEB) of pasteurized shelf-stable orange juice during storage. Various NEB precursors were used individually or in combinations to formulate simple or complex model systems, respectively, in citric acid buffer. Based on orange juice composition, ascorbic acid, sugars (sucrose, glucose and fructose) and amino acids (proline, arginine, asparagine, aspartic acid, serine and glutamic acid) were selected as the precursors for the model systems. After pasteurization and during subsequent accelerated storage (42 °C, 16 weeks) the model systems displayed a three-phase browning development. The initial browning phase was mainly the result of ascorbic acid degradation especially in the presence of amino acids and sugars. In the later phases, the contribution of reactions of sugars and amino acids to browning became apparent. The application of 1H NMR fingerprinting on a simple model system containing ascorbic acid revealed that its degradation pathway to intermediates such as xylonic acid, acetic acid and erythrulose was responsible for the major changes during storage. When this model system was complexed by inclusion of sugars and amino acids, the hydrolysis of sucrose to glucose and fructose was identified as the main reaction leading to differences in the samples throughout storage. These three sugars dominated the NMR spectra of the samples, overshadowing several important compounds for NEB such as ascorbic acid and its degradation products. Other more advanced NMR experiments such as two-dimensional NMR analyses should be applied in future research to identify unknown compounds from NEB reactions.

A benchtop single-sided magnet with NMR well-logging tool specifications - Examples of application.

This article was written in honor of Prof. Bernhard Blümich, who has heavily impacted many areas of Magnetic Resonance and, in particular, low-field and portable NMR with numerous advances, concepts, innovations, and applications of this impressive technology. Many years ago, we decided to research and develop single-sided magnets for the area of petroleum science and engineering to study oil reservoir rocks in the laboratory under well-logging conditions. The global urge to exploit oil reserves requires the analysis of reservoirs, intending to characterize the yields before starting the production. Thus, well-logging tools have been developed to estimate the quality of oil and reservoir productivity. NMR logging is included in these analytical tools, and numerous operations using this kind of device were performed since the early 1950s. To contribute to this vital research area, we show the development of a new benchtop single-sided NMR system, with well-logging tool characteristics, a cylindrical sweet spot with 4 cm of diameter and length, with magnetic field of 47 mT centered at 11 cm from the magnet's surface and a constant gradient of 35.7 G/cm along z. This system was used in self-diffusion, T1-T2, and D-T2 measurements of standard liquids and rock cores, demonstrating its functionality.

Measurement of long-range interatomic distances by solid-state tritium-NMR spectroscopy.

For the structural determination of a ligand bound to an amorphous macromolecular system, solid-state NMR can be used to provide interatomic distances. It is shown here that selective labeling in discrete locations with tritium enables accurate measurement of long-range distances owing to the high gyromagnetic ratio of this nucleus, without structural modification of the molecule. This approach gives access to the largest NMR distance ever measured between two nuclei (14.4 A). (3)H MAS NMR appears to be a promising tool for structural applications in the biological and material sciences.

Correlation of mechanical dyssynchrony with QRS duration measured by signal-averaged electrocardiography.

BACKGROUND: Preimplantation left ventricular dyssynchrony is considered a prerequisite for a beneficial response to cardiac resynchronization therapy (CRT). However, electrical dyssynchrony estimated by QRS duration (QRSd) on ECG has not been proven to be an optimal surrogate of mechanical dyssynchrony. We evaluated the correlation of mechanical dyssynchrony with QRSd as measured by signal-averaged electrocardiography (SAECG) in comparison with measurements based on conventional surface ECG and with onscreen measurements based on digital ECG. METHODS: We included 49 consecutive patients with decompensated heart failure (40 men, aged 66.8 +/- 9.5 years), New York Heart Association (NYHA) class II-IV, and LVEF < or = 40%. QRSd was calculated by manual measurement of 12-lead ECG, on-screen measurement of computer-based ECG, and calculation of total ventricular activation time on SAECG. RESULTS: Only 60.4% of the studied patients had QRS > or = 120 ms based on measurements derived by SAECG compared to 69.4% by using on-screen measurement of computer-based ECG and 73.5% based on surface ECG (P=0.041). Interventricular but not intraventricular delay was correlated with QRSd. The correlation of interventricular dyssynchrony with QRSd was stronger when measured by SAECG than by surface ECG (r=0.45, P=0.001 vs r=0.35, P < 0.01). Among patients with ischemic cardiomyopathy, no significant correlation was demonstrated between mechanical dyssynchrony and QRSd. In nonischemic patients, interventricular delay was significantly correlated with QRSd measured by surface ECG (r=0.45, P < 0.05) and SAECG (r=0.46, P < 0.05). CONCLUSIONS: The use of SAECG results in different patient classification in wide QRS complex category as compared to surface ECG. Furthermore, QRSd measured by SAECG is correlated with interventricular but not intraventricular dyssynchrony in heart failure patients.

Low-cost, pseudo-Halbach dipole magnets for NMR.

We present designs for compact, inexpensive and strong dipole permanent magnets aimed primarily at magnetic resonance applications where prepolarization and detection occur at different locations. Low-homogeneity magnets with a 7.5mm bore size and field up to nearly 2T are constructed using low-cost starting materials, standard workshop tools and only few hours of labor - an achievable project for a student or postdoc with spare time. As an application example we show how our magnet was used to polarize the nuclear spins in approximately 1mL of pure [13C]-methanol prior to detection of its high-resolution NMR spectrum at zero field (measurement field below 10-10T), where signals appear at multiples of the carbon-hydrogen spin-spin coupling frequency 1JCH=140.7(1)Hz.