Search

Simple Summary In many cancer cells, the choline uptake mechanism via the choline transporter-like protein 1 (CTL1) is involved in cell proliferation, and inhibiting its function is known to induce cell death by apoptosis. Therefore, CTL1 is attracting attention as a target molecule for cancer therapy. Here, we investigated the mechanism of the antitumor effect and metastasis inhibition of Amb544925, a novel CTL1 inhibitor discovered from plant-derived organic compounds in the tongue squamous cell carcinoma (TSCC) cell line, HSC-3. Amb544925 increased caspase-3/7 activity and caused apoptotic cell death. The antitumor effect of Amb544925 was brought about by suppressing the expression of survivin, an apoptosis inhibitor, through ceramide, an apoptosis-inducing factor (ceramide/survivin pathway). Furthermore, it was suggested that the inhibitory effect of Amb544925 on cell migration was also mediated by the ceramide/survivin pathway. Plant-derived Amb544925 is a lead compound in the treatment of TSCC that exerts antitumor effects via the ceramide/survivin pathway by targeting CTL1. Abstract Background: Despite recent advances in the early detection and treatment of TSCC patients, recurrence rates and survival rates have not improved. The high frequency of lymph node metastasis is one of the causes, and the drug development of new therapeutic mechanisms such as metastasis control is desired. Choline transporter-like protein 1 (CTL1) has attracted attention as a target molecule in cancer therapy. In this study, we examined the antitumor effects of Amb544925, a plant-derived CTL1 inhibitor. Methods: The TSCC cell line HSC-3 was used to measure [3H]choline uptake, cell survival, caspase activity, and cell migration. Xenograft model mice were prepared to verify the antitumor effect of Amb544925. Results: Amb544925 inhibited cell viability and increased caspase-3/7 activity at concentrations that inhibited choline uptake. Amb544925 and ceramide increased SMPD4 expression and suppressed surivivin expression. Furthermore, Amb544925 and ceramide inhibited the migration of HSC-3 cells. In the xenograft model mice, Amb544925 suppressed tumor growth and CTL1 mRNA expression. Conclusions: The plant-derived CTL1 inhibitor Amb544925 is a lead compound of a new anticancer agent exhibiting antitumor effects and inhibition of cell migration through the ceramide/survivin pathway.

α-Synuclein (αSyn) is an intrinsically disordered protein that can form amyloid fibrils. Fibrils of αSyn are implicated with the pathogenesis of Parkinson's disease and other synucleinopathies. Elucidating the mechanism of fibril formation of αSyn is therefore important for understanding the mechanism of the pathogenesis of these diseases. Fibril formation of αSyn is sensitive to solution conditions, suggesting that fibril formation of αSyn arises from the changes in its inherent physico-chemical properties, particularly its dynamic properties because intrinsically disordered proteins such as αSyn utilize their inherent flexibility to function. Characterizing these properties under various conditions should provide insights into the mechanism of fibril formation. Here, using the quasielastic neutron scattering and small-angle x-ray scattering techniques, we investigated the dynamic and structural properties of αSyn under the conditions, where mature fibrils are formed (pH 7.4 with a high salt concentration), where clumping of short fibrils occurs (pH 4.0), and where fibril formation is not completed (pH 7.4). The small-angle x-ray scattering measurements showed that the extended structures at pH 7.4 with a high salt concentration become compact at pH 4.0 and 7.4. The quasielastic neutron scattering measurements showed that both intra-molecular segmental motions and local motions such as side-chain motions are enhanced at pH 7.4 with a high salt concentration, compared to those at pH 7.4 without salt, whereas only the local motions are enhanced at pH 4.0. These results imply that fibril formation of αSyn requires not only the enhanced local motions but also the segmental motions such that proper inter-molecular interactions are possible.

We developed a quartz double cylindrical sample cell optimized for a backscattering neutron spectrometer, especially for BL02 (DNA), MLF in J-PARC. A quartz glass tube, with one end closed, is shaved to obtain a wall thickness of 0.55 mm. The inner tube is properly centered using a protrusion into the outer tube such that the interstice between the outer and inner tubes keeps constant. This quartz cell can be used for samples that should not be in contact with the aluminum surface. We verified cell's background effect between the quartz cell and Al cell by QENS measurements using D$_{2}$O buffer. The elastic intensity profiles of the buffer in a low Q region were identical between both quartz cell and Al cell (A1070). In a high Q region, however, the profiles were different caused by the first sharp diffraction peak of quartz glass. For this region the data should be analyzed by consideration of absorption correction and diffraction in individual thickness of quartz cell., 後方散乱型中性子分光器、特にJ-PARC MLFのBL02(DNA)分光器用に最適化された二重円筒型石英試料セルを開発した。一端を閉じられた石英ガラス管を0.55mmの厚みまで削り、内筒を底部の突起によって外筒に同芯になるように挿入する。この石英セルは、標準的に用いられているアルミセルの表面に触れさせたくない試料に用いられる。石英セルと標準アルミセルの容器散乱の効果を重水バッファ試料を使って中性子準弾性散乱実験(QENS)により確かめた。Qが1[1/A]未満の領域では石英セルとアルミ容器の弾性散乱プロファイルはほぼ同一であった。一方Qが1[1/A]以上の領域では、石英ガラスのFSDPのために、プロファイルが異なることが分かった。この領域では、吸収補正や石英セルの個々の厚みの差を考慮した解析が必要である。

"Water-in-salt" (WIS) and "water-in-bisalt" (WIBS) electrolytes have recently been developed for Li-ion batteries, combining the safety and environmental friendliness of aqueous electrolytes with a larger operating window made possible by a solid-electrolyte interphase. We report quasielastic neutron scattering (QENS) measurements on solutions of a WIS electrolyte at two concentrations, 13.9 and 21 m (molal) lithium bis(trifluoromethane)sulfonimide LiTFSI in H2O/D2O and a WIBS electrolyte at (21 m LiTFSI + 7 m lithium triflate (LiOTf)) in H2O/D2O. The data were Fourier transformed to obtain experimental intermediate scattering functions (ISFs) and compared with corresponding quantities obtained from molecular dynamics (MD) simulations. Both QENS and MD ISFs could be fitted well by a single stretched exponential function to obtain apparent translational diffusion coefficients for the water molecules. The QENS values agree well with the MD simulations for the 13.9 and 21 m solutions, but MD simulations predict a slower relaxation of water compared to QENS for the WIBS electrolyte. Comparison of the incoherent and coherent scattering reveals much faster water dynamics compared with structural relaxation of the ionic framework, consistent with the nanodomain picture where the lithium diffusion occurs through the tortuous water domain around the slower relaxing ionic matrix, leading to highly non-Gaussian water motion.

Choline, an organic cation, is one of the biofactors that play an important role in the structure and the function of biological membranes, and it is essential for the synthesis of phospholipids. Choline positron emission tomography-computed tomography (PET/CT) provides useful information for the imaging diagnosis of cancers, and increased choline accumulation has been identified in a variety of tumors. However, the molecular mechanisms of choline uptake and choline transporters in pancreatic cancer have not been elucidated. Here, we examined molecular and functional analyses of choline transporters in human pancreatic-cancer cell line MIA PaCa-2 and the elucidation of the action mechanism behind the antitumor effect of novel choline-transporter-like protein 1 (CTL1) inhibitors, Amb4269951 and its derivative Amb4269675. CTL1 and CTL2 mRNAs were highly expressed in MIA PaCa-2 cells, and CTL1 and CTL2 proteins were localized in the plasma membrane and the intracellular compartments, respectively. Choline uptake was characterized by Na+-independence, a single-uptake mechanism, and inhibition by choline-uptake inhibitor HC-3, similar to the function of CTL1. These results suggest that the uptake of extracellular choline in MIA PaCa-2 cells is mediated by CTL1. Choline deficiency and HC-3 treatment inhibited cell viability and increased caspase 3/7 activity, suggesting that the inhibition of CTL1 function, which is responsible for choline transport, leads to apoptosis-induced cell death. Both Amb4269951 and Amb4269675 inhibited choline uptake and cell viability and increased caspase-3/7 activity. Ceramide, which is increased by inhibiting choline uptake, also inhibited cell survival and increased caspase-3/7 activity. Lastly, both Amb4269951 and Amb4269675 significantly inhibited tumor growth in a mouse-xenograft model without any adverse effects such as weight loss. CTL1 is a target molecule for the treatment of pancreatic cancer, and its inhibitors Amb4269951 and Amb4269675 are novel lead compounds.

Choline transporter-like protein 1 (CTL1) is highly expressed in glioma cells, and inhibition of CTL1 function induces apoptotic cell death. Therefore, CTL1 is a potential target molecule for glioma therapy. Here, we investigated the therapeutic mechanism underlying the antitumor effects of Amb4269951, a recently discovered novel CTL1 inhibitor, in the human glioma cell line U251MG, and evaluated its in vivo effects in a mouse xenograft model. Amb4269951 inhibited choline uptake and cell viability and increased caspase-3/7 activity. CTL1-mediated choline uptake is associated with cell viability, and the functional inhibition of CTL1 by Amb4269951 may promote apoptotic cell death via ceramide-induced suppression of the expression of survivin, an apoptotic inhibitory factor. Finally, Amb4269951 demonstrated an antitumor effect in a mice xenograft model by significantly inhibiting tumor growth without any weight loss. Amb4269951 is the lead compound in the treatment of glioma and exhibits a novel therapeutic mechanism. These results may lead to the development of novel anticancer drugs targeting the choline transporter CTL1, which has a different mechanism of action than conventional anticancer drugs against gliomas.

Quasielastic neutron scattering is applied to analyse the atomic scale hydrogen transport processes occurring within the crystal lattices of hydrous minerals. Two types of transport processes were observed in Mg(OH)2, which has a prototypical layered hydrogen lattice structure., It is demonstrated that quasielastic neutron scattering is a novel and effective method to analyse atomic scale hydrogen transport processes occurring within a mineral crystal lattice. The method was previously characterized as sensitive for analysing the transport frequency and distance of highly diffusive hydrogen atoms or water molecules in condensed matter. Here are shown the results of its application to analyse the transport of much slower hydrogen atoms which are bonded into a crystal lattice as hydroxyls. Two types of hydrogen transport process were observed in brucite, Mg(OH)2: a jump within a single two-dimensional layer of the hydrogen lattice and a jump into the next nearest layer of it. These transport processes observed within the prototypical structure of brucite have direct implications for hydrogen transport phenomena occurring within various types of oxides and minerals having layered structures.

The dynamics of methanol confined in highly cross-linked phenolic resins was investigated using incoherent quasielastic neutron scattering (QENS) and atomistic molecular dynamics (MD) simulations. ...

Nano-confined water (a water pocket) was spontaneously formed using an ionic liquid (IL), 1-butyl-3-methylimidazolium nitrate ([C4mim][NO3]), in [C4mim][NO3]-H2O and [C4mim][NO3]-D2O mixtures. The static average size of the water pocket in [C4mim][NO3]-80 mol% D2O has been estimated to be around 20 A, determined via small-angle neutron scattering measurements (Abe et al., J. Phys. Chem. Lett., 2014, 5, 1175). In this study, the dynamics of the water pocket in the IL were directly examined using incoherent quasielastic neutron scattering. Using the H-D difference of a neutron incoherent scattering cross section, the extent of the diffusion of the water molecules in the water pocket was determined. The water pocket could be characterized due to the slow dynamics of the water compared with those of bulk water.

Dynamics of a fluoromica (ME100) cation exchanged for dioctadecyl dimethyl ammonium ion (DODA+)/polypropylene composite was analyzed by quasi elastic neutron scattering (QENS), besides XRD and DSC. The QENS spectra for the DODA-ME100 at low Q = 2.75 nm− 1 were not changed even at temperature higher than 445 K, the melting point of DODA+. The results suggested the long range (> 2 nm) molecular motions in interlayer space are restricted due to the rigid silicate layers and the strong electrostatic interaction between DODA+ and the ME100. Elastic intensity scan results suggested that a little amount of motion of the polymer chains in the composite was also restricted in the molten state at 445 K. The QENS is expected to be one of the useful tools for studying the composite materials.

Quasi-elastic neutron scattering (QENS) and pulsed-field-gradient nuclear magnetic resonance (PFG-NMR) analyses of a nanofluid composed of silicon dioxide (SiO2) nanoparticles (sized 100, 300, or 500 nm) and a base fluid of ethylene glycol aqueous solution were performed. The aim was to elucidate the mechanism increase in the thermal conductivity of the nanofluid above its theoretical value. Typically, the self-diffusion coefficient of liquid molecules in nanofluids can indicate the effect of the nanoparticles on thermal transport in nanofluids as well as the molecular dynamics of the liquid surrounding the nanoparticles. At 298 and 333 K, the obtained experimental results indicate that SiO2 particles may decrease the self-diffusion coefficient of the liquid molecules in the ethylene glycol aqueous solution because of their highly restricted motion around these nanoparticles. The self-diffusion coefficient of the liquid molecules comprising 300 nm-sized particles is lower than that of the nanofluids comprising 100 and 500 nm-sized particles. At a constant temperature, the thermal conductivity increases as the self-diffusion coefficient of the liquid molecules decreases in the SiO2 nanofluids.

J-PARC, Japan Proton Accelerator Research Complex provides short pulse proton beam at a repetition rate 25Hz and the maximum power is expected to be 1MW. Materials and Life Science Experimental Facility (MLF) has 23 neutron beam ports and 21 instruments have already been operated or under construction/commissioning. There are 6 inelastic/quasi-elastic neutron scattering spectrometers and the complementary use of these spectrometers will open new insight for life science.This article is part of a Special Issue entitled “Science for Life” Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo.

Ionic liquids (ILs) are potential candidates for new antimicrobials due to their tunable antibacterial and antifungal properties that are required to keep pace with the growing challenge of bacterial resistance. To a great extent their antimicrobial actions are related to the interactions of ILs with cell membranes. Here, we report the effects of ILs on the nanoscopic dynamics and phase behaviour of a dimyristoylphosphatidylcholine (DMPC) membrane, a model cell membrane, as studied using neutron scattering techniques. Two prototypical imidazolium-based ILs 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM[BF4]) and 1-decyl-3-methylimidazolium tetrafluoroborate (DMIM[BF4]), which differ only in terms of the alkyl chain length of cations, have been used for the present study. Fixed Elastic Window Scan (FEWS) shows that the incorporation of ILs affects the phase behaviour of the phospholipid membrane significantly and the transition from a solid gel to a fluid phase shifts to lower temperature. This is found to be consistent with our differential scanning calorimetry measurements. DMIM[BF4], which has a longer alkyl chain cation, affects the phase behaviour more strongly in comparison to BMIM[BF4]. The pressure-area isotherms of the DMPC monolayer measured at the air-water interface show that in the presence of ILs, isotherms shift towards higher area-per lipid molecule. DMIM[BF4] is found to shift the isotherm to a greater extent compared to BMIM[BF4]. Quasielastic neutron scattering (QENS) data show that both ILs act as a plasticizer, which enhances the fluidity of the membrane. DMIM[BF4] is found to be a stronger plasticizing agent in comparison to BMIM[BF4] that has a cation with a shorter alkyl chain. The incorporation of DMIM[BF4] enhances not only the long range lateral motion but also the localised internal motion of the lipids. On the other hand, BMIM[BF4] acts weakly in comparison to DMIM[BF4] and mainly alters the localised internal motion of the lipids. Any subtle change in the dynamical properties of the membrane can profoundly affect the stability of the cell. Hence, the dominant effect of the IL with the longer chain length on the dynamics of the phospholipid membrane might be correlated with its cytotoxic activity. QENS data analysis has provided a quantitative description of the effects of the two imidazolium-based ILs on the dynamical and phase behaviour of the model cell membrane, which is essential for a detailed understanding of their action mechanism.

Characterization of the dynamics of disordered polypeptide chains is required to elucidate the behavior of intrinsically disordered proteins and proteins under non-native states related to the folding process. Here we develop a method using quasielastic neutron scattering, combined with small-angle X-ray scattering and dynamic light scattering, to evaluate segmental motions of proteins as well as diffusion of the entire molecules and local side-chain motions. We apply this method to RNase A under the unfolded and molten-globule (MG) states. The diffusion coefficients arising from the segmental motions are evaluated and found to be different between the unfolded and MG states. The values obtained here are consistent with those obtained using the fluorescence-based techniques. These results demonstrate not only feasibility of this method but also usefulness to characterize the behavior of proteins under various disordered states.

Sagittal split ramus osteotomy and intraoral vertical ramus osteotomy are commonly performed for the correction of jaw deformities. However, during mandibular orthognathic surgeries such as sagittal split ramus osteotomy and intraoral vertical ramus osteotomy , the authors sometimes encounter exposure of the buccal fat pad (BFP), which decreases the surgical field. The exposed BFP makes it difficult to perform these operations, may result in unexpected complications, and may increase the operation time. Therefore, the authors herein describe a simple, safe, and convenient technique for reducing the volume of the exposed BFP during mandibular orthognathic surgery using an electric knife in the coagulation mode.

We studied the dynamics of zinc diacrylate (ZDA) reinforced polybutadiene rubber (BR) (ZDA/BR) using the quasielastic neutron scattering technique to determine the effect of concentration of ZDA on polymer dynamics. First, we evaluated the temperature dependence of mean square displacements (〈u2〉) for ZDA/BR with different ZDA volume fractions. 〈u2〉 increased with temperature below 170 K, and we observed no significant ZDA volume fraction dependence. However, it increased more steeply above 170 K, and the value of 〈u2〉 was smaller for the samples with increasing ZDA fraction. To elucidate the origin of the decrease in 〈u2〉 with increasing ZDA content, dynamic scattering laws (S(Q,ω)) were analyzed. An increase in the elastic component, an increase in the mean relaxation time, and a broadening of distribution of relaxation time were observed with the increasing volume fraction of ZDA. In addition, the ZDA volume fraction dependence of the elastic component roughly corresponded to that of elastic modulus, indicating that the elastic component is related to its mechanical strength. Referring to the previously reported static structure of the present ZDA/BR system, a model for the heterogeneous BR dynamics was proposed. This model assumes the coexistence of immobile, mobile, and interfacial constrained mobile regions. It was found to be appropriate for the explanation of the observed dynamics. We proposed that a network-like structure of the BR having a high crosslinking density around ZDA aggregates is mainly responsible for the high elastic modulus of ZDA/BR.

In this study, we investigate the \ensuremath{\alpha} process of a polystyrene thin film using inelastic neutron scattering (INS), dielectric relaxation spectroscopy (DRS), and thermal expansion spectroscopy (TES). The DRS and TES measurements exhibited a decrease in glass transition temperature (${T}_{\mathrm{g}}$) with film thickness. On the other hand, an increase in ${T}_{\mathrm{g}}$ was observed in INS studies. In order to interpret this contradiction, we investigated the temperature dependence of the peak frequency (${f}_{\mathrm{m}}$) of the \ensuremath{\alpha} process probed by DRS and TES. The experiments revealed an increase in the peak frequency (${f}_{\mathrm{m}}$) with decreasing film thickness in the frequency region. This observation is consistent with the observed decrease in ${T}_{\mathrm{g}}$ with thickness. Interestingly, the increase in ${T}_{\mathrm{g}}$ with film thickness was confirmed by fitting the temperature dependence measurements of the peak frequency with the Vogel-Fulcher-Tammann equation, within the frequency region probed by INS. The discrepancy between INS and DRS or TES descriptions of the \ensuremath{\alpha} process is likely to be attributed to a decrease in the apparent activation energy with film thickness and reduced mobility, due to the impenetrable wall effect.

Hemoglobin, the vital O2 carrier in red blood cells, has long served as a classic example of an allosteric protein. Although high-resolution X-ray structural models are currently available for both the deoxy tense (T) and fully liganded relaxed (R) states of hemoglobin, much less is known about their dynamics, especially on the picosecond to subnanosecond time scales. Here, we investigate the picosecond dynamics of the deoxy and CO forms of human hemoglobin using quasielastic neutron scattering under near physiological conditions in order to extract the dynamics changes upon ligation. From the analysis of the global motions, we found that whereas the apparent diffusion coefficients of the deoxy form can be described by assuming translational and rotational diffusion of a rigid body, those of the CO form need to involve an additional contribution of internal large-scale motions. We also found that the local dynamics in the deoxy and CO forms are very similar in amplitude but are slightly lower in frequency...

Neutron devices such as neutron detectors, optical devices including supermirror devices and 3He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC), Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF.

Perovskite CH3NH3PbI3 exhibits outstanding photovoltaic performances, but the understanding of the atomic motions remains inadequate even though they take a fundamental role in transport properties. Here, we present a complete atomic dynamic picture consisting of molecular jumping rotational modes and phonons, which is established by carrying out high-resolution time-of-flight quasi-elastic and inelastic neutron scattering measurements in a wide energy window ranging from 0.0036 to 54 meV on a large single crystal sample, respectively. The ultrafast orientational disorder of molecular dipoles, activated at ∼165 K, acts as an additional scattering source for optical phonons as well as for charge carriers. It is revealed that acoustic phonons dominate the thermal transport, rather than optical phonons due to sub-picosecond lifetimes. These microscopic insights provide a solid standing point, on which perovskite solar cells can be understood more accurately and their performances are perhaps further optimized. Clarifying the atomistic behaviour of materials will lead to a deeper fundamental understanding and the rational design of future materials. Using time-of-flight quasi-elastic and inelastic neutron scattering measurements Liet al. study the atomic motions of metal-halide perovskite CH3NH3PbI3.

Troponin (Tn), consisting of three subunits (TnC, TnI, and TnT), regulates cardiac muscle contraction in a Ca2+-dependent manner. Various point mutations of human cardiac Tn are known to cause familial hypertrophic cardiomyopathy due to aberration of the regulatory function. In this study, we investigated the effects of one of these mutations, K247R of TnT, on the picosecond dynamics of the Tn core domain (Tn-CD), consisting of TnC, TnI and TnT2 (183–288 residues of TnT), by carrying out the quasielastic neutron scattering measurements on the reconstituted Tn-CD containing either the wild-type TnT2 (wtTn-CD) or the mutant TnT2 (K247R-Tn-CD) in the absence and presence of Ca2+. It was found that Ca2+-binding to the wtTn-CD decreases the residence time of atomic motions in the Tn-CD with slight changes in amplitudes, suggesting that the regulatory function mainly requires modulation of frequency of atomic motions. On the other hand, the K247R-Tn-CD shows different dynamic behavior from that of the wtTn-CD both in the absence and presence of Ca2+. In particular, the K247R-Tn-CD exhibits a larger amplitude than the wtTn-CD in the presence of Ca2+, suggesting that the mutant can explore larger conformational space than the wild-type. This increased flexibility should be relevant to the functional aberration of this mutant.

The nuclear and magnetic structure and full magnon dispersions of yttrium iron garnet Y$_3$Fe$_5$O$_{12}$ have been studied by neutron scattering. The refined nuclear structure is distorted to a trigonal space group of $R\bar{3}$. The highest-energy dispersion extends up to 86 meV. The observed dispersions are reproduced by a simple model with three nearest-neighbor-exchange integrals between 16$a$ (octahedral) and 24$d$ (tetrahedral) sites, $J_{aa}$, $J_{ad}$, and $J_{dd}$, which are estimated to be 0.00$\pm$0.05, $-$2.90$\pm$0.07, and $-$0.35$\pm$0.08 meV, respectively. The lowest-energy dispersion below 14 meV exhibits a quadratic dispersion as expected from ferromagnetic magnons. The imaginary part of $q$-integrated dynamical spin susceptibility $\chi$"($E$) exhibits a square-root energy-dependence in the low energies. The magnon density of state is estimated from the $\chi$"($E$) obtained on an absolute scale. The value is consistent with a single polarization mode for the magnon branch expected theoretically., Comment: 9 pages, 9 figures

The influence of water on the relaxation of a prototype ionic liquid (IL) C8mimBF4 is examined in the IL-rich regime combining quasi-elastic neutron scattering (QENS) and molecular dynamics (MD) simulations. The QENS and MD simulations results for relaxation of IL and the equimolar mixture with water probed by the dynamics of the C8mim hydrogen atoms in the time range of 2 ps to 1 ns are in excellent agreement. The QENS data show that translational relaxation increases by a factor of 7 on the addition of water, while rotational relaxation involving multiple processes fitted by a KWW function with low β values is speeded up by a factor of 3 on the time scale of QENS measurements. The MD simulations show that the cation diffusion coefficient, inverse viscosity, and ionic conductivity increase on the addition of water, consistent with the very small change in ionicity. The difficulties in obtaining rotational and translational diffusion coefficients from fits to QENS experiments of pure ILs and IL–water mixt...

The dynamical correlation function, , of liquid germanium at 1500°C is obtained from the Fourier transform using experimental . The limiting value for time to zero of was compared with experimental . From this result, the validity of present is confirmed. From the result of , the value of correlation of located between and decreases up to around 0.8 psec and increases as time increases afterwards. From this fact, the result of suggests that, especially in the short range of time, the single free particle behaviour is relatively included in the collective motion of germanium ions at this radius region.

From the quasi-elastic neutron scattering experiment, dynamic structure factors, S(Q, E) were obtained at both 1000°C and 1500°C. To understand the distribution of the dynamic structure factor as a scattering low, the half-width at half-maximum (HWHM) of dynamic structure factor was determined. It is clear that the Q dependence for HWHM of S(Q, E) does not fulfil the rigorous definition on the condition of the phenomenon called the de Gennes narrowing. From the Fourier transform, the intermediate scattering function, F(Q, t), is obtained. From the result of F(Q, t), it is clear that the relaxation process of liquid germanium is different from that of simple liquid.

Perovskite CH3NH3PbI3 exhibits outstanding photovoltaic performances, but the understanding of the atomic motions remains inadequate even though they take a fundamental role in transport properties. Here, we present a complete atomic dynamic picture consisting of molecular jumping rotational modes and phonons, which is established by carrying out high-resolution time-of-flight quasi-elastic and inelastic neutron scattering measurements in a wide energy window ranging from 0.0036 to 54 meV on a large single crystal sample, respectively. The ultrafast orientational disorder of molecular dipoles, activated at ∼165 K, acts as an additional scattering source for optical phonons as well as for charge carriers. It is revealed that acoustic phonons dominate the thermal transport, rather than optical phonons due to sub-picosecond lifetimes. These microscopic insights provide a solid standing point, on which perovskite solar cells can be understood more accurately and their performances are perhaps further optimized., Clarifying the atomistic behaviour of materials will lead to a deeper fundamental understanding and the rational design of future materials. Using time-of-flight quasi-elastic and inelastic neutron scattering measurements Li et al. study the atomic motions of metal-halide perovskite CH3NH3PbI3.

Differential scanning calorimetry, X-ray diffraction, and quasi-elastic neutron scattering (QENS) measurements of aqueous glycine solutions confined in mesoporous silica (MCM-41) were performed at different glycine concentrations, pH, and loading ratio (=mass of glycine solution/mass of dry MCM-41) in the temperature range from 305 to 180 K to discuss the confinement effect on the thermal behavior, the structure, and the dynamic properties of the solutions. The freezing points of the confined glycine solutions decreased, compared with those of the bulk solutions. The corresponding exothermic peak due to ice formation became broader with an increase in the glycine concentration. By subtracting X-ray diffraction patterns of dry MCM-41 from those of glycine solution-loaded MCM-41, information about the structure of the confined glycine solutions was obtained. The radial distribution functions of the confined glycine solutions showed that the peaks assigned to the interaction between glycine molecules and the surface silanol (Si-OH) groups of MCM-41 at pH = 5 were observed, in contrast to the case at pH = 2. The QENS data on H/D substituted aqueous glycine solutions gave the translational diffusion coefficients and the residence time of glycine and water molecules confined in MCM-41 individually. The activation energy of the diffusion coefficient of a glycine molecule at pH = 5 was larger than that at pH = 2. These results imply that glycine molecules locate near the pore surface of MCM-41 due to the formation of hydrogen bonding between glycine molecules and the silanol group of the MCM-41 wall at pH = 5.

Alkyl-methyl-imidazolium ionic liquids CnmimX (n: alkyl-carbon number, X: anion) have short-range layer structures consisting of ionic and neutral (alkylchain) domains. To investigate the temperature dependences of the interlayer, interionic group, and inter-alkylchain correlations, we have measured the neutron diffraction (ND) of C16mimPF6, C9.5mimPF6, and C8mimPF6 in the temperature region from 4 K to 470 K. The quasielastic neutron scattering (QENS) of C16mimPF6 was also measured to study the dynamics of each correlation. C16mimPF6 shows a first-order transition between the liquid (L) and liquid crystalline (LC) phases at Tc = 394 K. C8mimPF6 exhibits a glass transition at Tg = 200 K. C9.5mimPF6, which is a 1:3 mixture between C8mimPF6 and C10mimPF6, has both transitions at Tc = 225 K and Tg = 203 K. In the ND experiments, all samples exhibit three peaks corresponding to the correlations mentioned above. The widths of the interlayer peak at ca. 0.2 A−1 changed drastically at the L-LC transitions, while the interionic peaks at ca. 1 A−1 exhibited a small jump at Tc. The peak position and area of the three peaks did not change much at the transition. The structural changes were minimal at Tg. The QENS experiments demonstrated that the relaxation time of the interlayer motion increased tenfold at Tc, while those of other motions were monotonous in the whole temperature region. The structural and dynamical changes mentioned above are characteristic of the L-LC transition in imidazolium-based ionic liquids.Alkyl-methyl-imidazolium ionic liquids CnmimX (n: alkyl-carbon number, X: anion) have short-range layer structures consisting of ionic and neutral (alkylchain) domains. To investigate the temperature dependences of the interlayer, interionic group, and inter-alkylchain correlations, we have measured the neutron diffraction (ND) of C16mimPF6, C9.5mimPF6, and C8mimPF6 in the temperature region from 4 K to 470 K. The quasielastic neutron scattering (QENS) of C16mimPF6 was also measured to study the dynamics of each correlation. C16mimPF6 shows a first-order transition between the liquid (L) and liquid crystalline (LC) phases at Tc = 394 K. C8mimPF6 exhibits a glass transition at Tg = 200 K. C9.5mimPF6, which is a 1:3 mixture between C8mimPF6 and C10mimPF6, has both transitions at Tc = 225 K and Tg = 203 K. In the ND experiments, all samples exhibit three peaks corresponding to the correlations mentioned above. The widths of the interlayer peak at ca. 0.2 A−1 changed drastically at the L-LC transitions, while...

To illuminate ionic conduction behavior of super protonic phase of CsH 2 PO 4 (CDP), quasi-elastic neutron scattering (QENS), pulse field gradient nuclear magnetic resonance (PFG-NMR) and 1 H NMR spin-lattice relaxation time ( T 1 ) measurements were carried out. Diffusion coefficient of protons obtained from PFG-NMR reproduced well the electrical conductivity by using Nernst–Einstein equation. Comparison of PFG-NMR and T 1 provided a hopping distance of protons as 2.7 A, which agreed with the next nearest proton sites in CDP. On the other hand, QENS data was fitted well with a jump-diffusion model. Comparison of the jump diffusion coefficient and the correlation time obtained by QENS provided a librational correlation time of protons in the order of 10 − 12 s. The present investigation suggests that different techniques, QENS and NMR, can observe protonic motions having different time constants including librational and translational motions within the hydrogen bonding network of CDP.

Quasi-elastic neutron scattering measurements have been performed in order to investigate ionic dynamics in molten CuI at 650 °C. The prominent elastic contribution was observed at around 0.85 A −1 , where the partial structure factor of the Cu–Cu correlation has the first sharp diffraction peak. The analysis of the relaxation time in the intermediate scattering functions deduced from the quasi-elastic scattering spectra reveals that molten CuI exhibits extremely slow dynamics with the characteristic relaxation time over 1 ps in this Q -region, which is much longer than the self-diffusion of Cu ions.

We have developed a novel configuration concept of crystal chips for time-of-flight (TOF) crystal-analyzer neutron inelastic scattering spectrometers, which simultaneously achieve time-focusing, spatial-focusing and momentum-correcting abilities. This concept will be adopted for the planned TOF near-backscattering spectrometer, DIANA which has been proposed for construction at the Japan Proton Accelerator Research Complex (J-PARC). We will first discuss the new analyzer layout method satisfying both time- and spatial-focusing and momentum-correction concepts and then the focusing performances as evaluated by Monte-Carlo simulations and compared to the generally used energy-focusing analyzer configuration.

The instrumental design of an indirect geometry crystal analyzer spectrometer: DNA which is scheduled to be constructed in the Material and Life Science experimental Facility (MLF) at J-PARC, is reported in this article. This spectrometer is mainly aimed at searching for the biomolecular dynamics related to its functionality. Therefore, it is requested to measure the high quality inelastic scattering spectra with only several mg order biomolecular sample in the plenty of wide range of energy and momentum transfers.

Quasicrystals are long-range-ordered materials that lack translational invariance, so the study of their physical properties remains a challenging problem. Here, we have carried out inelastic-X-ray- and neutron-scattering experiments on single-grain samples of the Zn-Mg-Sc icosahedral quasicrystal and of the Zn-Sc periodic cubic 1/1 approximant, with the aim of studying the respective influence of the local order and of the long-range order (periodic or quasiperiodic) on lattice dynamics. Besides the overall similarities and the existence of a pseudo-gap in the transverse dispersion relation, marked differences are observed, the pseudo-gap being larger and better defined in the approximant than in the quasicrystal. This can be qualitatively explained using the concept of a pseudo-Brillouin-zone in the quasicrystal. These results are compared with simulations on atomic models and using oscillating pair potentials, and the simulations reproduce in detail the experimental results. This paves the way for a detailed understanding of the physics of quasicrystals.

A near-backscattering (n-BS) crystal-analyzer neutron inelastic spectrometer, DIANA, has been proposed for construction at Japan Proton Accelerator Research Complex. It has originally been designed to view a decoupled non-poisoned moderator in order to obtain high intensity and good energy resolution. Recently, we have reconsidered the instrumental parameters including the type of moderator, by performing Monte-Carlo simulations in order to obtain better performance. Among four virtual n-BS spectrometers on different beam sources moderators, a coupled-moderator-source spectrometer has shown the best performance, i.e. compared to the original DIADA design between ninefold and fivefold enhanced intensities have been obtained with 21%-better to 35%-worse energy resolutions.

A way to address the problem of phonons in quasicrystals (QCs) is to compare their dynamical response with that of approximant crystalline structures. Although the Zn2Mg Laves phase is not a periodic approximant of a QC phase, its structure is a periodic packing of Friauf polyhedra which are basic units involved in the construction of larger icosahedral atomic clusters found in Frank–Kasper type quasicrystals. We report on the experimental study of the lattice dynamics of the Zn2Mg hexagonal phase using inelastic neutron scattering with a particular attention devoted to the behavior of transverse acoustic (TA) modes. For TA modes propagating along the (T) direction, polarized along the c axis, there is a strong bending of the dispersion curve. Whereas the broadening rate is rather slow, going like q2, a strong coupling of the acoustic mode with an higher energy optical mode takes place. For TA modes propagating along the (Δ) direction, polarized in the hexagonal plane, the dispersion relation reaches much higher energy: the broadening rate is however steeper, going like q4, most likely due to a mixing of several excitations in the spectral response. In any case, the width of acoustic and optical excitations is found much smaller than in quasicrystals.

DIANA is an indirect geometry TOF spectrometer which will be installed at Materials and Life science experimental Facility (MLF), Japan Proton Accelerator Research Complex (J-PARC). We are especially aiming at high energy resolution of about 2 μeV by using perfect crystal Si(111) analyzer together with high speed counter-rotating pulse-shaping choppers with each rotation frequency of 300 Hz as optional equipments. Although such a high energy resolution is attained, it is considerably inefficient to chop a very narrow incident energy band from one pulse period of a source. Therefore, we have varied the number of slits and have performed Monte Carlo simulations to study repetition rate multiplication (RRM) capabilities. By using the optimum 8-slit pulse-shaping choppers, 23 incident energy bands are simultaneously available from one pulse period of a source. It will give us better measurement efficiency when investigating between quasi-elastic and low energy inelastic regions of about 3 meV with high energy...

Designing the next generation of lithium ion batteries requires fundamental information that surprisingly often is still unknown---for example, details of how ions actually move through a working device. The authors use state-of-the-art quasielastic neutron scattering to directly monitor the fast diffusion of Li${}^{+}$ in a promising solid electrolyte. Here the ions migrate between stable regions within a jump length $llg$ = 4.3 \AA{} along conduction pathways that thread stacks of tetrahedral motifs in the crystal structure. This understanding is key to improved energy storage for applications ranging from vehicles to future smart grids.

The facility has resumed since 17th February 2014 after reformation of operation safety system required from the new regulation because of the accident in the Hadron Facility in May 2013. During eight-month shutdown period various hardware components have been improved; such as installation of additional RFQs in Linac to increase its energy to achieve higher power, repairing and replacement on the mercury (Hg) cooling loops of the neutron target, improvement on the cryogenic system for stable operation, etc. In order to mitigate the pitting damage on the Hg-target container we have been injecting helium micro bubbles in the target. The laser Doppler vibrometory showed us that vibration on the proton bombardment has been drastically reduced by the injection. Twenty one instruments have been already installed. Sixteen instruments are operated for user program and four instruments are under either commissioning or construction. Now the experimental hall is almost full with instruments, leaving only 2 ports available for the future use. Operational time for user program in JFY2014 was about 170 days, and we received more than 700 general experimental proposals from users. World-class scientific outputs have been being created in various scientific fields, ranging from Li-battery science to bio-molecular science. Since J-PARC is internationally open for users, we have got experimental proposals from abroad, which are more than 15% of the whole proposals. More than 20% of proposals have come from industries and a half of them are proprietary use. This fact has revealed a new horizon has come in the neutron scattering science in the 21 century.

The time-of-flight (TOF) type near-backscattering spectrometer (n-BSS), DNA, with Si crystal analyzers was built and started operation in 2012 at the Materials and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). DNA is the first n-BSS with pulse shaping chopper installed at a spallation pulsed neutron source. It offers currently the highest energy-resolution of about 2.4 micro eV by operating a pulse shaping double-disk chopper at 225 Hz whose phase is optimized to the narrowest slit of 10 mm width. Energy resolution can be flexibly compromised with intensity during experiment by using two type slits with different widths and changing the copper frequency. An example of measurement with high energy-resolution under the condition that the pulse shaping chopper was operated is shown, where the limited measurable energy range was widely expanded by multi incident energy band technique. The experimental data demonstrate extremely high signal-to-noise ratio (~10 5 ) of this spectrometer.