Differentiation Between Hepatocellular Carcinoma and Colorectal Cancer Liver Metastases on High-Resolution Magic Angle Spinning Spectroscopy: Preliminary Study

To explore the potential of high-resolution magic angle spinning (HRMAS) ¹H nuclear magnetic resonance (NMR) spectroscopy for differentiation and metabolite characterization of hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM), we prospectively included 21 pathologically confirmed malignant hepatic tumors (8 HCC and 13 CRLM) and 26 non-tumorous hepatic parenchyma from 26 patients who underwent hepatic tumor resection. Using intact tissue samples obtained during surgery, HRMAS ¹H NMR spectroscopy was performed at 11.7 T. All observable metabolite signals were acquired using a water-presaturated standard one-dimensional Carr–Purcell–Meiboom–Gill sequence. Metabolomic profiles contributing to the differentiation of HCC and CRLM and of each tumor and non-tumorous hepatic parenchyma were represented by orthogonal partial least squares discriminant analysis (OPLS-DA) and loading plots. Metabolite intensity normalized by total spectral intensities in both tumors was compared using student’s t tests. OPLS-DA and loading plots demonstrated good separation between tumors and non-tumorous hepatic parenchyma. The metabolomic characteristics of HCC showed separation from those of CRLMs according to OPLS-DA. Compared with CRLM, HCC showed significantly elevated levels of glucose (P < 0.01) and sn-Glycero-3-phosphocholine (P < 0.01), and decreased levels of hypoxanthine (P = 0.04). HCC and CRLM could be differentiated by the metabolic profile using HRMAS ¹H NMR spectroscopy.     

Finding confined water in the hexagonal phase of Bi0.05Eu0.05Y0.90PO4·xH2O and its impact for identifying the location of luminescence quencher

¹H MAS NMR spectra of Bi_0.05Eu_0.05Y_0.90PO₄·xH₂O show chemical shift from ?0.56 ppm at 300 K to ?3.8 ppm at 215 K and another one at 5–6 ppm, which are related to the confined or interstitial water in the hexagonal structure and water molecules on the surface of the particles, respectively. Negative value of the chemical shift indicates that H of H₂O is closer to metal ions (Y^3?+? or Eu^3?+?), which is a source of luminescence quencher. H coupling and decoupling ³¹P MAS NMR spectra at 300 and 250 K show the same chemical shift (?0.4 ppm) indicating that there is no direct bond between P and H. It is concluded that the confined water is not frozen even at 215 K because of the less number of H-bonding.     

Solid-state Fluorescence Emission and Second-Order Nonlinear Optical Properties of Coumarin-based Fluorophores

Some coumarin-based fluorophores were synthesized and characterized by elemental analysis, ¹H NMR, ¹³C NMR and MS. The solid-state photoluminescence properties were studied. The benzocoumarins display interesting solid-state emission properties with an emission at wavelengths ranging from 532 to 645 nm, when excited by a 325 nm helium–cadmium laser at room temperature. The results demonstrated that the luminescent colors can be tuned from green to red by simply varying molecular structure. The benzocoumarin-phenyl boronic acid hybrid, 4-(3-oxo-3-(2 -oxo-2H-1-naphtho[2,1-b]pyran-3-yl)-prop-1-enyl)phenyl boronic acid, showed obvious fluorescence response to water. Whereas the free compound was very weakly fluorescent in tetrahydrofuran (THF), the addition of water leads to an appearance of strong blue-green fluorescence and a dramatic increase of emission intensity. Besides, 3-(3-(3,4,5-trimethoxyphenyl)-prop-2-enoyl)-2H-1-benzopyran-2-one exhibited second order nonlinear optical response to laser pulses. A noticeable second harmonic generation (SHG) under pulsed excitation at 1064 nm was observed. Preliminary nonlinear measurements on powder samples showed that the second harmonic generation efficiency is roughly 5.8 times that of potassium dihydrogen phosphate (KDP).     

Proton dynamics in one-dimensional hydrogen-bonding system in molecular co-crystals TMP-D2ca and DMP-H2ca

The proton dynamics in one-dimensional hydrogen-bonding system in molecular co-crystals of tetramethylpyrazine (TMP) with chloranilic acid (H₂ca), as well as 2,6-dimethylpyrazine (DMP) with H₂ca is studied by ³⁵Cl NQR and ²H NMR spin-lattice relaxation measurements. No transfer motion of proton between the acid and base molecules is observed in DMP-H₂ca, while the motion of the acid proton is excited in TMP-H₂ca and the activation energy for the motion increases from 35 kJ mol^???1 to 50 kJ mol^???1 by the deuteration.     

1H NMR Study of Zeolite Water Structure and Broensted Acid Centers in Chabazite

The disordered structure of absorbed water in a highly porous zeolite chabazite Ca₂[Al₄Si₈O₂₄]·nH₂O (2 ≤ n ≤ 12.8) is studied from motionally narrowed ¹H nuclear magnetic resonance spectra at room temperature. Concentration phase transitions were observed at n ≈ 8.3 and n ≈ 10.2. The transitions are accompanied by displacement of Ca²⁺ ions and variation of the Broensted acid centers at inner surface of zeolite pores.     

H/D isotope effect of 1H MAS NMR spectra and 79Br NQR frequencies of piperidinium p-bromobenzoate and pyrrolidinium p-bromobenzoate

H/D isotope effects onto ⁷⁹Br NQR frequencies of piperidinium p-bromobenzoate were studied by deuterium substitution of hydrogen atoms which form two kinds of N–H?O type hydrogen bonds, and the isotope shift of ca. 100 kHz were detected for a whole observed temperature range. In addition, ¹H MAS NMR spectra measurements of piperidinium and pyrrolidinium p-bromobenzoate were carried out and little isotope changes of NMR line shape were detected. In order to reveal effects of molecular arrangements into the obtained isotope shift of NQR frequencies, single-crystal X-ray measurement of piperidinium p-bromobenzoate-d2 and density-functional-theory calculation were carried out. Our estimation showed the dihedral-angle change between piperidine and benzene ring contributes to isotope shift rather than those of N–H lengths by deuterium substitution.     

Molecular Mobility in Amorphous Polylactic Acid Studied Using <Superscript>1</Superscript>H–<Superscript>13</Superscript>C Cross Polarization NMR

The ¹H–¹³C cross polarization nuclear magnetic resonance technique was used for the study of molecular mobility in amorphous polylactic acid. The cross polarization buildup curves for methine and methyl functional groups measured at magic angle spinning rates of 4 and 10 kHz, under Hartmann–Hahn conditions determined from corresponding Hartmann–Hahn matching profiles, confirmed the presence of ¹H–¹³C spin pairs isolated from lattice since transient oscillations were observed in the initial stages of buildup curves. The values of dipolar coupling constants derived from Fourier transforms of cross polarization buildup curves indicate the presence of rigid methine groups and two kinds of methyl functional groups which differ in mobility. This could be due to the presence of amorphous phase with chain aggregations and phase with less spatial restrictions in this material. Fitting of theoretical expressions to experimental data provided additional information on the cross polarization process in this material.     

127I NQR and 1H NMR studies of 4-aminopyridinium tetraiodoantimonate(III); molecular motion and phase transition

The crystals of 4-NH₂PyHSbI₄ (Py = C₅H₄N) have been investigated by means of ¹²⁷I NQR, ¹H NMR T ₁ and DTA. The crystals can exist in two modifications of β and α(I) at room temperatures. The α(I)-phase is a metastable state which is obtained when the stable β form is heated. The α(I)-phase undergoes a first-order type phase transition of α(I) $\leftrightarrow \alpha $ (II) at 272 K (on heating), while the β-phase is stable down to 77 K. Four and two ¹²⁷I (m = ±1/2 $\leftrightarrow \pm $ 3/2) NQR lines have been found for the β- and α(II)-phases, respectively. One half of them is assignable to the terminal I atom(s) and the other to the bridging I atom(s) in each phase. All the resonance lines of the α(II)-phase underwent a disappearance above ca. 240 K and no resonance line was observed in the α(I)-phase. The second moment M ₂ value of ¹H NMR spectra with 8 G² at 290 K shows that the 4-NH₂PyH^?+? cations reside in the rigid lattice in the β-phase. In contrast, in the α(I)-phase the cation rotates about an axis more symmetric than pseudo threefold axis. The activation energy of 21 kJ mol^???1 was estimated for the reorientational motion in the α(I)-phase from the ¹H NMR T ₁ measurements. The nature of phase transitions in the 4-NH₂PyHSbI₄ is discussed in comparison with that in 4-NH₂PyHSbBr₄.     

Development of a Single-Sided Nuclear Magnetic Resonance Scanner for the In Vivo Quantification of Live Cattle Marbling

Non-invasive in vivo marbling quantification helps owners to choose the optimum nutritional management for growing cattle and buyers to more precisely evaluate grown cattle at auctions. When using time-domain proton nuclear magnetic resonance (NMR) relaxometry, it is possible to quantify muscle and fat separately by taking advantage of the difference in the spin–spin relaxation time (T2) between water molecules in muscles and fat molecules, which would contribute to the non-invasive and objective determination of marbling scores. With this in mind, we developed a prototype NMR scanner (4.1 MHz for protons) using an original single-sided magnetic circuit and a plane radio frequency (RF) coil for use in the non-invasive quantification of water and fat in live cattle. The sensed region of the developed scanner is compact and almost cubical (19 × 19 × 16 mm³) while the investigation depth (the distance from the RF coil to the center of the sensed region) has been lengthened to 30 mm, which is sufficient for the in vivo trapezius muscle measurement of live cattle. Measurements of 17 samples of beef meat blocks kept at 39 °C were taken in a laboratory to successfully obtain the calibration lines used to convert the NMR signals into water and fat weight fractions at correlation coefficients in excess of 0.9. We also showed that each meat sample could be measured in about 10 s with a measurement error as small as approximately 10 wt%. Accordingly, we believe that our prototype scanner would be useful for in vivo marbling measurements of live cattle trapezius muscles.     

An easily Prepared Fluorescent pH Probe Based on Dansyl

A novel fluorescent pH probe from dansyl chloride and thiosemicarbazide was easily prepared and fully characterized by ¹H NMR, ¹³C NMR, LC-MS, Infrared spectra and elemental analysis. The probe exhibited high selectivity and sensitivity to H⁺ with a pK _a value of 4.98. The fluorescence intensity at 510 nm quenched 99.5 % when the pH dropped from 10.88 to 1.98. In addition, the dansyl-based probe could respond quickly and reversibly to the pH variation and various common metal ions showed negligible interference. The recognition could be ascribed to the intramolecular charge transfer caused by the protonation of the nitrogen in the dimethylamino group.     

83mKr, a potentially powerful PAC probe

In the decay of ⁸³Rb to ^83mKr and the subsequent decay to the ⁸³Kr ground state a 553–9.4 keV γ-γ and a 17.85–9.4 keV e^?-γ cascade are populated. The intermediate 9.4 keV 7/2^?+? state with a half-life of 154 ns is a perfect candidate for the application of the perturbed angular correlation (PAC) technique. Thus, it is possible to investigate the lattice environment of the implanted probes via the electric quadrupole interaction of the 9.4 keV 7/2^?+? state with the electric field gradient produced by the host lattices. Details of the production of this new PAC probe and planned measurements will be discussed.     

Repeated-Binge Ethanol Intoxication Leads to Lower Choline-Containing Compound Signals in Adult Rats: An In Vivo Marker of Ethanol-Induced Neurochemical Abnormalities

Ethanol is the most commonly abused intoxicating substance among young and middle-aged adults, and ranks highly as a cause of disability and mortality. A pattern of heavy consumption, called binge drinking, leads to various psychiatric disorders. However, to the best of our knowledge, assessments of the influence of short-term binge ethanol (SBE) intoxication on cerebral metabolite changes in human and rat models are scarce. We used in vivo ¹H magnetic resonance spectroscopy (¹H-MRS) to quantitatively assess neurochemical responses in hippocampus in a rat model of SBE intoxication. Seven SBE-exposed rats received an initial dose of 5.0-g/kg ethanol (30 %-w/v solution) through gavage and additional doses of 2.0-g/kg ethanol (25 %-w/v solution), every 8 hour for 4 days. Six rats in sham control group (CNTL) received an equivalent volume of distilled water at comparable times. Sixty minutes after last gavage session, in vivo ¹H-MRS scans were obtained from all rats using a 4.7 Tesla animal scanner. For neurochemical analysis, a single voxel was positioned in the hippocampal region and spectra were fitted for the quantification of 17 cerebral neurochemical signals. In hippocampus, the concentration of total choline-containing compound signals (tCho: [glycerophosphocholine] + [phosphocholine]) was significantly lower in SBE-exposed rats than in CNTL rats. Moreover, gamma-aminobutyric acid (GABA)/total creatine (tCr: creatine + phosphocreatine), tCho/tCr, and tCho/total N-acetyl-aspartate (tNAA: N-acetyl-aspartate + N-acetyl-aspartyl-glutamate) ratios were significantly lower in SBE-exposed rats than CNTL rats. We determined that tCho, GABA, and tNAA signals were highly sensitive to short-term binge ethanol intoxication, which provides insights into neurochemical alterations associated with ethanol abuse.     

Application of z-COSY experiment and its variant for accurate chiral discrimination by 1H NMR

We report the application of z-COSY experiment and a band selected version of it by employing a selective 90° pulse entitled BASE-z-COSY for precise chiral discrimination, quantification of enantiomeric excess and the analyses of the ¹H NMR spectra of chiral molecules aligned in the chiral liquid crystalline solvent poly-γ-benzyl-l-glutamate (PBLG). We have demonstrated their applicability for obtaining very high resolution in the ¹H NMR spectra of small organic molecules. It is well known that the commonly employed z-COSY experiment disentangles the spectral complexity, provides pure phase spectra with high resolution, aids in the complete spectral analyses, in addition to yielding information on relative signs of the couplings. The BASE-z-COSY experiment possesses all these properties, permits the measure of enantiomeric excess, in addition to large saving of instrument time.     

NMR studies of magnetic properties in Heusler-type Mn 3 Si

In order to microscopically investigate the magnetic properties of both paramagnetic and antiferromagnetic phases in Mn₃Si (T _N?=?23 K), the ⁵⁵Mn NMR has been carried out at temperatures between 2.2 K and 300 K. The temperature dependences of the spectrum, Knight shift (or resonance frequency shift) and spin-lattice relaxation time T ₁ of ⁵⁵Mn NMR have been measured. In the paramagnetic phase, only one resonance spectrum can be obtained. The observed spectrum is identified to be a signal corresponding to the Mn(II) site. In the antiferromagnetic phase, two different spectra corresponding to the Mn(I) and Mn(II) sites are found at the resonance frequencies of 145 and 6 MHz, respectively, by the zero field NMR at 4.2 K. From these results, the internal magnetic fields on the ⁵⁵Mn(I) and ⁵⁵Mn(II) nuclei are found to be 13.6 and 0.6 T, respectively. According to the NMR results, the helical structure in incommensurate Mn spin states is better explained compared with the transverse sinusoidal structure.     

Development of poly(glycerol suberate) polyester (PGS)–PVA blend polymer electrolytes with NH<Subscript>4</Subscript>SCN and its application

Besides commercially available synthetic polymers, the present work has been undertaken to explore the significance of poly(glycerol suberate) (PGS) polyester synthesised under lab scale in energy storage device. In this regard, a blend polymer electrolyte comprising of polyvinyl alcohol (PVA), poly(glycerol suberate) (PGS) polyester along with the various proportions of ammonium thiocyanate (NH₄SCN) was prepared adopting solution casting technique. The synthesised polyester PGS was characterised by Fourier transform infrared (FT-IR) spectroscopy, ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy. The prepared electrolyte film was subjected to FT-IR analysis to study the complexation that has occurred within the blend. Its amorphous nature was revealed from X-ray diffraction (XRD) studies. Influence of NH₄SCN on the glass transition temperature (T_g) was drawn from differential scanning calorimetry (DSC) technique. The dispersion of dopant within the polymer matrix was supported by scanning electron microscopy (SEM) followed by its elemental composition from energy dispersive spectroscopy (EDS). From the AC impedance technique, maximum conductivity of 3.01?×?10^?4 S cm^?1 was elicited for the optimised electrolyte (1 g PVA?+?0.75 g PGS?+?0.6 g NH₄SCN). Frequency-dependent dielectric and modulus spectra were analysed to study the mechanism of transportation. Transport parameters evaluated by Wagner’s polarisation method proved that the conductivity was predominantly due to cations. Proton conducting battery was configured with the highest conducting electrolytic film and its cell parameters are presented.     

Phase transition and proton exchange in 1,3-diazinium hydrogen chloranilate monohydrate

In the hydrate crystal of 1:1 salt with 1,3-diazine and chloranilic acid (H₂ca), (1,3-diazineH)·H₂O·Hca, an unique hydrogen-bonded molecular aggregate is formed. There exists proton disorder in the N–H...O hydrogen bond between 1,3-diazinium ion and water (H₂O) of crystallization. In order to reveal dynamic aspect of this disorder, ³⁵Cl NQR measurements were conducted. Two resonance lines observed at 35.973 and 35.449 MHz at 321 K split into four lines below T _c?=?198 K clearly showing occurrence of a solid–solid phase transition; 36.565, 36.357, 36.011, 35.974 MHz at 77 K. Temperature dependence of spin-lattice relaxation time T ₁ in high-temperature phase was observed to obey an Arrhenius-type relation with the activation energy of 8.5 kJ mol^???1. This result leads to the conclusion that proton exchange in the N–H...O hydrogen bond takes place in the high-temperature phase. Specific heat measurements by DSC resulted in the transition entropy ΔS?=?1.3 J K^???1 per 1 mole [(1,3-diazineH)·H₂O·Hca]₂ which is far less than 2R ln2 = 11.5 J K^???1 mol^???1. It is expected that proton exchange in the two hydrogen bonds within the aggregate does not occur independently but concertedly with strong correlation in the high-temperature phase.     

Firing-Induced Microstructural Properties of Quasi-Diamagnetic Carbonate-Based Porous Ceramics: a <Superscript>1</Superscript>H NMR Relaxation Correlation Study

This study deals with the application of two-dimensional proton nuclear magnetic resonance relaxometry (2D ¹H NMR-R) to the characterization of porous ceramics nearly free of magnetic compounds. Different microstructural properties were obtained by firing a diamagnetic mixture of kaolin, calcium, and magnesium carbonate over a wide range of maximum temperatures (600–1100 °C) and firing times at the maximum temperature (soaking times) (0–10 h). The 2D ¹H NMR-R method relies on the correlated measurement of ¹H longitudinal (T ₁) and transverse (T ₂) relaxation times of pore-filling water by which the properties of the interconnected pore space may be investigated. In the absence of significant magnetic susceptibility effect due to para- and ferro-magnetic compounds, the 2D ¹H NMR-R maps allow studying the conjoint effects on pore size distribution and inter-pore coupling due to the variations in both time and temperature of firing. The NMR experiments were performed with a low-field ¹H NMR sensor, which allows non-destructive and in situ analysis. For ceramic specimens fired at 600 and 700 °C, the fraction of smallest pores increases with firing time at the expenses of those with intermediate size. The pore shrinkage occurring at this stage, and likely associated with the transformation of kaolinite in metakaolinite, is affected in a similar way by soaking time and firing temperature, in line with the concept of equivalent firing temperature. At temperatures from 800 to 1100 °C, the structural modifications involving interconnectivity and average pore size are driven primarily by firing temperature and, secondarily, by soaking time. The 2D ¹H NMR-R results are confirmed by more traditional, but destructive, mineralogical, and structural analyses like X-ray powder diffraction, helium pycnometry, mercury intrusion porosimetry, and nitrogen adsorption/desorption method.     

Threshold 3He and 3H Transverse Electron Scattering Response Functions

The threshold transverse response functions R _T (q, ω) for ³He and ³H are calculated using the AV18 nucleon–nucleon potential, the UrbanaIX three-body force, and the Coulomb potential. Final states are completely taken into account via the Lorentz integral transform technique. Consistent two-body π- and ρ-meson exchange currents as deduced using the Arenhövel-Schwamb technique are included. The convergence of the method is shown and a comparison of the corresponding MEC contribution is made to that of a consistent MEC for the meson theoretical r-space BonnA potential. The response R _T is calculated in the threshold region at q = 174, 324, and 487 MeV/c and compared with available data. The strong MEC contributions in the threshold region are nicely confirmed by the data at q = 324 and 487 MeV/c although some differences between theoretical and experimental results remain. A comparison is also made with other calculations, where the same theoretical input is used. The agreement is generally rather good, but leaves also some space for further improvement.     

1H MAS, 13C CP/MAS, and 2H NMR spectra studies of piperidinium {\emph{p}}-chlorobenzoate

Anomalous H/D isotope effects were detected in the ¹H MAS NMR spectra of piperidinium p-chlorobenzoate (C₅H₁₀NH $_{2}{^{+}}\cdot $ ClC₆H₄COO^???) upon deuterium substitution of hydrogen atoms which form two kinds of N-H?O H-bonds in the crystal; in contrast to these spectra, only slight chemical shifts were recorded in ¹³C CP/MAS NMR spectra. ²H NMR spectrum of the deuterated sample show quadrupole coupling constants of 148 and 108 kHz, and reveal that there are a few motions contributing to the electric-field modulation of the ²H nucleus. The ¹H MAS NMR spectra of piperidinium p-chlrobenzoate-d ₁₆ (C₅D₁₀ND $_{2}{^{+}}\cdot $ ClC₆D₄COO^???) and -d ₁₄ (C₅D₁₀NH $_{2}{^{+}}\cdot $ ClC₆D₄COO^???) revealed that the change in the envelope is caused by chemical shifts of each signal upon deuteration. Calculations based on the density-functional-theory showed that the N-H distance along the crystallographic a-axis mainly contributes to the anomalous isotope effects on ¹H MAS NMR envelopes.     

<Superscript>15</Superscript>N–<Superscript>13</Superscript>C Dipole Couplings in Smectic Mesophase of a Thermotropic Ionic Liquid

Unique combination of ionic conductivity and anisotropic physical properties in ionic liquid crystals leads to new dynamic properties exploited in modern technological applications. Structural and dynamics information at atomic level for molecules and ions in mesophases can be obtained by nuclear magnetic resonance (NMR) spectroscopy through the measurements of dipole–dipole spin couplings. While ¹³C–¹H and ¹⁵N–¹H dipolar NMR spectra can be routinely acquired in samples with natural isotopic abundance, recording ¹⁵N–¹³C dipolar NMR spectra is challenging because of the unfavourable combination of two rare isotopes. In the present study, an approach to measure ¹⁵N–¹³C dipole-dipole NMR spectra in static liquid crystalline samples with natural abundance is introduced. We demonstrate that well-resolved spectra can be recorded within 10 h of experimental time using a conventional NMR probe and a moderately strong magnetic field. The technique is applied to a thermotropic smectic mesophase formed by an ionic liquid with imidazolium-based organic cation.