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The crystal growth of urea was analyzed with all-atom molecular dynamics (MD) simulation for the (001) and (110) faces in contact with aqueous solutions. The local environment of a crystallizing molecule was treated in terms of the numbers of crystalline neighbors and the orientation relative to the crystal surface, and the molecular-level inhomogeneity of a growing surface was addressed by decomposing the overall rate of growth into a sum of the contributions conditioned by the local structure and orientation mode. The contrast of the growth mechanism between the (001) and (110) faces was then evidenced by the local contributions, and the roles of the outer layers of the crystal toward the liquid region were pointed out for (001). The effect of the additive species in the liquid on the crystal growth of urea was investigated with biuret

Elucidating the state of interfacial water, especially the hydrogen-bond configurations, is considered to be key for a better understanding of the functions of polymers that are exhibited in the presence of water. Here, an analysis in this direction is conducted for two water-insoluble biocompatible polymers, poly(2-methoxyethyl acrylate) and cyclic(poly(2-methoxyethyl acrylate)), and a non-biocompatible polymer, poly(

Redox-active PdII3-macrocycle crystals were found to provide an excellent platform for gold reduction and growth of immobilized particles, leading to the one-step synthesis of stable, monodisperse, Konpeito-shaped gold nanoparticles.

Reentrant phenomena in soft matter and biosystems have attracted considerable attention because their properties are closely related to high functionality. Here, we report a combined experimental and computational study on the self-assembly and reentrant behavior of a single-component thermotropic smectic liquid crystal toward the realization of dynamically functional materials. We have designed and synthesized a mesogenic molecule consisting of an alicyclic trans,trans -bicyclohexyl mesogen and a polar cyclic carbonate group connected by a flexible tetra(oxyethylene) spacer. The molecule exhibits an unprecedented sequence of layered smectic phases, in the order: smectic A-smectic B-reentrant smectic A. Electron density profiles and large-scale molecular dynamics simulations indicate that competition between the stacking of bicyclohexyl mesogens and the conformational flexibility of tetra(oxyethylene) chains induces this unusual reentrant behavior. Ion-conductive reentrant liquid-crystalline materials have been developed, which undergo the multistep conductivity changes in response to temperature. The reentrant liquid crystals have potential as new mesogenic materials exhibiting switching functions.

A key to achieve the accuracy of molecular dynamics (MD) simulation is the set of force fields used to express the atomistic interactions. In particular, the electrostatic interaction remains the main issue for the precise simulation of various ionic soft materials from ionic liquids to their supramolecular compounds. In this study, we test the nonpolarizable force fields of ionic liquids (ILs) and self-assembled ionic liquid crystals (ILCs) for which the intermolecular charge transfer and intramolecular polarization are significant. The self-consistent modeling scheme is adopted to refine the atomic charges of ionic species in a condensed state through the use of density functional theory (DFT) under the periodic boundary condition. The atomic charges of the generalized amber force field (GAFF) are effectively updated to express the electrostatic properties of ionic molecules obtained by the DFT calculation in condensed phase, which improves the prediction accuracy of ionic conductivity with the obtained force field (GAFF-DFT). The derived DFT charges then suggest that the substitution of a hydrophobic liquid-crystalline moiety into IL-based cations enhances the charge localization of ionic groups in the amphiphilic molecules, leading to the amplification of the electrostatic interactions among the hydrophilic/ionic groups in the presence of hydrophobic moieties. In addition, we focus on an ion-conductive pathway hidden in the self-assembled nanostructure. The MD results indicate that the ionic groups of cation and anion interact strongly for keeping the bicontinuous nanosegregation of ionic nanochannel. The partial fractions of hydrophilic/ionic and hydrophobic nanodomains are then quantified with the volume difference from referenced IL systems, while the calculated ionic conductivity decreases in the self-assembled ILCs more than the occupied volume of ionic nanodomains. These analyses suggest that the mobility of ions in the self-assembled ILCs remains quite restricted even with small tetrafluoroborate anions because of strong attractive interaction among ionic moieties.

The Stokes-Einstein (SE) relation for pure liquids of various non-spherical molecules is examined using molecular dynamics simulation. The SE relation obeys generally the equation recently proposed...

The nonpolarizable force field of ionic liquids is tuned by using the self-consistent scheme of molecular dynamics (MD) simulation and first-principles calculation based on the order-N density func...

The development of technologies for nuclear reactors based on molten salts has seen a big resurgence. The success of thermodynamic models for these hinges in part on our ability to predict at the a...

Purpose In order to evaluate the movement strategy in sit-to-stand (STS) motion, it is necessary to measure the center of gravity (COG). However, there is no established method for enabling this using convenience device in the clinical setting. The purpose of this study was to validate the measurement of the COG during the STS motion using an inexpensive, portable and markerless motion capture system (MLS). Method Eighteen healthy adults participated in our study. The coordinates of the joint centers during the STS motion were collected using the Microsoft Kinect system (as a MLS) and the Vicon system (as a marker-based motion capture system [MBS]). The center of mass of each segment—which was calculated based on the segmental mass and length—were synthesized to calculate the COG. The displacement, velocity, acceleration of the COG during the STS motion were calculated from the data obtained using each system and compared between systems. Results The two systems showed significant difference in their measurements of displacement in both the vertical and anteroposterior directions. However, in the anteroposterior direction, there was no significant difference in the measurements of either velocity or acceleration. Conclusion Our results suggested the validity of the COG in the anteroposterior direction during the STS motion measured using the MLS. The method developed in the present study enables the evaluation of a patient's movement strategy.

Background Fractional exhaled nitric oxide concentration (FeNO) is widely used to support diagnosis and monitoring of bronchial asthma (BA). Tsoukias and George proposed a two‐compartment model (2CM) for assessing the alveolar concentration of NO, referred to as CANO(2CM), while Condorelli et al proposed a model based on the trumpet shape of the airway tree and axial diffusion (TMAD), referred to as CANO(TMAD). In addition, Högman et al proposed non‐linear model, referred to as CANO(non‐linear). Objective We examined associations between the expression of inducible nitric oxide synthase (iNOS) mRNA in airway cells (ACs) by bronchoscopy and NO‐parameters calculated by the three methods and identified which of them accurately reflected expression of iNOS mRNA from different airway portions. Methods We retrospectively analysed data of 18 patients with stable, mild‐moderate asthma, including 10 steroid‐naïve BA (snBA) patients. Samples were obtained from airway brushings and bronchoalveolar lavage (BAL). Expressions of iNOS protein in tissue samples were evaluated by immunostaining. The iNOS mRNA in ACs was measured by qPCR. NO‐parameters calculated by the three methods above and evaluated whether they were associated with iNOS mRNA in ACs derived from proximal (2nd carina), distal (10‐15th) airways and alveolar regions. Results Immunostaining revealed expression of iNOS proteins mainly in epithelial cells in the airways, while it was mainly expressed in macrophages in the alveolar region in the snBA group. The iNOS mRNA expression was increased in both proximal and distal ACs in the snBA group compared with steroid‐treated BA group (stBA). CANO(2CM) negatively associated with FEV 1 (%predicted) and also associated with iNOS mRNA in distal ACs significantly. However, CANO(TMAD) and CANO(non‐linear) showed no correlation with lung function nor iNOS mRNA expression in any portions of ACs. Conclusions These results suggested that CANO(2CM) reflected distal airway inflammation in steroid‐naïve asthma.

Ionic liquid (IL)-based electrolytes are a promising material for the development of sodium-ion batteries, and their performance can be quantified by electrical conductivity. In this highly concentrated ionic system, the correlated motions of ion pairs are influential on the ionic transport properties. Herein, all-atom analyses are conducted through molecular dynamics simulations to bridge the macroscopically observable electrical conductivity with the molecular pictures of correlated motion of ion pairs. The analysis is applied to three mixtures of IL with sodium salt that are relevant to the electrolyte for a sodium-ion battery: [1-ethyl-3-methylimidazolium, Na][bis(fluorosulfonyl)amide] ([C

Ionic liquid (IL) has been considered as a potential electrolyte for developing next-generation sodium-ion batteries. A highly concentrated ionic system such as IL is characterized by the significant influence of intramolecular polarization and intermolecular charge transfer that vary with the combination of cations and anions in the system. In this work, a self-consistent atomic charge determination using the combination of classical molecular dynamics (MD) simulation and density functional theory (DFT) calculation is employed to investigate the transport properties of three mixtures of ILs with sodium salt relevant to the electrolyte for a sodium-ion battery: [1-ethyl-3-methylimidazolium, Na][bis(fluorosulfonyl)amide] ([C2C1im, Na][FSA]), [N-methyl-N-propylpyrrolidinium, Na][FSA] ([C3C1pyrr, Na][FSA]), and [K, Na][FSA]. The self-consistent method is versatile to address the intramolecular polarization and intermolecular charge transfer in response to the cation-anion combination, as well as the variation in their compositions. The structure and dynamic properties of IL mixtures obtained from the method are in line with those from the experimental works. The comparison to the Nernst-Einstein estimates shows that the electrical conductivity is reduced due to correlated motions among the ions, and the contribution to the conductivity from each ion species is not necessarily ranked in the same order as the diffusion coefficient. It is further seen that the increase of the sodium-ion composition reduces the fluidity of the system. The results highlight the potential of the method and the microscopic description that it can provide to assist the investigation toward a sensible design of IL mixtures as an electrolyte for a high-performance sodium-ion battery.

Yellow nail syndrome (YNS) pleurisy is often difficult to control, and pathological examinations have rarely been reported. We herein report a case of bucillamine-induced YNS in which histopathology of the parietal pleura revealed hyperplasia of the lymphoid follicles and lymphangiectasia. Even after the discontinuation of bucillamine, the pleurisy and lymphedema showed no change. Based on the histopathological findings showing similarity to rheumatoid pleurisy, we administered corticosteroid treatments, and both the pleurisy and lymphedema improved. The findings in the present case suggest that, in bucillamine-induced YNS, pleurisy may be related to inflammation caused by rheumatoid arthritis in addition to abnormalities in lymphatic vessels.

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology which accounts for a large proportion of cases of idiopathic interstitial pneumonia. It has a very poor prognosis with a 5-year survival rate of 30% or below, and so far there has been no guideline in Japan offering an established effective therapy based on evidence. In addition to the establishment of basic therapies, there is also an urgent need to establish therapies to deal with complications, as death occurs in many cases due to acute exacerbation or comorbid lung cancer. It was therefore decided to formulate a guideline in order to promote evidence-based clinical practice, to further improve the quality of medical treatment in the clinical setting, and to allow the benefits to be enjoyed by the public.

The nematic-isotropic (NI) phase transition of 4-cyano-4'-pentylbiphenyl (5CB) was simulated using the generalized replica-exchange method (gREM) based on molecular dynamics simulations. The effective temperature is introduced in gREM, allowing the enhanced sampling of configurations in the unstable region, which is intrinsic to the first-order phase transition. The sampling performance was analyzed with different system sizes and compared with that of the temperature replica-exchange method (tREM). It was observed that gREM is capable of sampling configurations at sufficient replica-exchange acceptance ratios even around the NI transition temperature. A bimodal distribution of the order parameter at the transition region was found, which is in agreement with the mean-field theory. In contrast, tREM is ineffective around the transition temperature owing to the potential energy gap between the nematic and isotropic phases., 7 pages, 5 figures, 2 tables, to appear in J. Chem. Phys

The present study evaluates the thermal design of a blanket system using Flinabe in order to facilitate further discussions on its applicability as a self-cooled liquid blanket system. Molecular dynamics simulations were performed to evaluate the Prandtl number of mixtures in five compositions (LiF–NaF–BeF2 = 31–31–38, 36–27–37, 42–22–36, 49–16–35, and 67–0–33). Thermofluid analysis was carried out to estimate the temperature margin and pressure drop per unit length in a simple geometry model of the blanket system. The Prandtl number of Flinabe is above 100 at 400°C. The present study reveals that Flinabe remarkably relaxes the design conditions compared to Flibe as a coolant owing to its low melting point. In contrast, the pressure drop per unit length of Flinabe is higher than that of Flibe because the viscosity exponentially increases at low temperature. The temperature margin is quite dependent on the heat load on the first wall. If the pressure drop per unit length is around 1.0 MPa/m, the he...

The development of technologies for nuclear reactors based on molten salts has seen a big resurgence. The success of thermodynamic models for these hinges in part on our ability to predict at the atomistic level the behavior of pure salts and their mixtures under a range of conditions. In this letter, we present high-energy X-ray scattering experiments and molecular dynamics simulations that describe the molten structure of mixtures of MgCl

A spatially resolved version of the density-functional method for solvation thermodynamics is presented by extending the free-energy functional previously established in the one-dimensional, energy representation and formulating a new expression in a mixed four-dimensional representation (three dimensions for position and one dimension for energy). The space was further divided into a set of discrete regions with respect to the relative position of a solvent molecule from the solute, and the spatially decomposed energetics of solvation were analyzed for small molecules with a methyl, amine, or hydroxyl group and alanine dipeptide in solvent water. It was observed that the density of the solvation free energy is weakly dependent on the solute site in the excluded-volume region and is distinctively favorable in the first shells of the solute atoms that can readily form hydrogen bonds with water. The solvent-reorganization term reduces faster with the separation from the solute than the direct interaction between the solute and solvent, and the latter governs the energetics in the second shell and outer regions. The sum of the contributions to the free energy from the excluded volume and first shell was found to deviate significantly from the total sum over all the regions, implying that the solvation free energy is not spatially localized near the solute in a quantitative sense. Still, a local description was shown to be valid as confirmed by the correlation of the total value of free energy with the corresponding value obtained by integrating the free-energy density to the second shell. The theoretical framework developed in the present work to spatially decompose the solvation free energy can thus be useful to identify stabilizing or destabilizing regions of solvent proximate to a solute and to analyze the role that the displacement of interfacial water plays in the thermodynamics of molecular association.

Through molecular dynamics simulations, we examined hydrodynamic behavior of the Brownian motion of fullerene particles based on molecular interactions. The solvation free energy and the velocity autocorrelation function (VACF) were calculated by using the Lennard-Jones (LJ) and Weeks-Chandler-Andersen (WCA) potentials for the solute-solvent and solvent-solvent interactions and by changing the size of the fullerene particles. We also measured the diffusion constant of the fullerene particles and the shear viscosity of the host fluid, and then the hydrodynamic radius $a_\mathrm{HD}$ was quantified from the Stokes-Einstein relation. The $a_\mathrm{HD}$ value exceeds that of the gyration radius of the fullerene when the solvation free energy exhibits largely negative values using the LJ potential. In contrast, $a_\mathrm{HD}$ becomes comparable to the size of bare fullerene, when the solvation free energy is positive using the WCA potential. Furthermore, the VACF of the fullerene particles is directly comparable with the analytical expressions utilizing the Navier-Stokes equations both in incompressible and compressible forms. Hydrodynamic long-time tail $t^{-3/2}$ is demonstrated for timescales longer than the kinematic time of the momentum diffusion over the particles' size. However, the VACF in shorter timescales deviates from the hydrodynamic description, particularly for smaller fullerene particles and for the LJ potential. This occurs even though the compressible effect is considered when characterizing the decay of VACF around the sound propagation time scale over the particles' size. These results indicate that the nanoscale Brownian motion is influenced by the solvation structure around the solute particles originating from the molecular interaction., 11 pages, 7 figures, to appear in Soft Matter

Induced pluripotent stem cells (iPSCs) are opening up new possibilities for medicine. Understanding the regulation of iPSC biology is important when attempting to apply these cells to disease models or therapy. Changes of lipid metabolism in iPSCs were investigated by matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF-IMS). Analysis revealed changes of the intensity and distribution of peaks at m/z 782.5 and 798.5 in iPSC colonies during spontaneous differentiation. Two phosphatidylcholines (PCs) were identified: C44H81NO8P, PC(36:4)[M+H]+ at m/z 782.5 and C42H82NO8P, PC(34:1)[M+K]+ at m/z 798.5. The intensity of PC(36:4) showed an inverse relation between undifferentiated and differentiated iPSC colonies. PC(34:1) displayed a diffuse distribution in undifferentiated iPSC colonies, while it showed a concentric distribution in differentiated iPSC colonies, and was localized at the border of the differentiated and undifferentiated areas or the border between undifferentiated iPSC and feeder cells. These findings suggested that the distribution of lipids changes during the growth and differentiation of iPSCs and that MALDI-TOF-IMS was useful for analyzing these changes. PC(36:4) might play a role in maintaining pluripotency, while PC(34:1) might play a role in the differentiation and spread of iPSCs.

Background and objective:The calcium-binding protein S100A4 belongs to the S100 family and is involved in fibrotic and inflammatory processes, in which tissue remodeling, cell motility, and epithelialmesenchymal transition play major roles. Cytoplasmic S100A4 is a marker of lung fibroblasts in pulmonary fibrosis;however, the effects of exogenous S100A4 on fibrotic and inflammatory processes in pulmonary fibrosis are unclear. This study examined the effects of exogenous S100A4 protein in mice with bleomycin-induced pulmonary fibrosis.Methods:Bleomycin was administered to mice by intratracheal instillation on day 1. Intratracheal S100A4 protein was administered 4 times after bleomycin treatment. Bronchoalveolar lavage fluid was obtained and lung histological examinations were performed on day 14 after bleomycin administration. Lung tissue was homogenized on the same day to assess the mRNA expression of cytokines, fibroblast growth factors, and S100A4.Results:Unexpectedly, we observed that the administration of exogenous S100A4 protein apparently reduced lung fibrosis in bleomycin-treated mice. In addition, the levels of lymphocyte accumulation and insulin-like growth factor-1 mRNA were significantly reduced in bleomycin-treated lung by S100A4 administration.Conclusions:Exogenous S100A4 protein attenuates bleomycin-induced pulmonary fibrosis in mice by reducing lymphocyte function and the levels of fibroblast growth factors.

To clarify the clinical features of organizing pneumonia (OP) associated with rheumatoid arthritis (RA) and to determine whether development of OP is related to RA activity.A cross-sectional study was conducted, in which medical records of 499 consecutive RA patients who visited our hospital during one month were reviewed. OP was diagnosed by pathological findings by trans-bronchial biopsy or by clinical features (typical computed tomography findings, no causative agents, good response to glucocorticoids, and lack of response to antibiotics).Among 499 patients, OP was found in 19 patients and the estimated prevalence was 1.9-4.8%. No differences in clinical features were noted between the OP and non-OP groups. The mean age of OP development was 57.2 years and the period from the onset of RA to OP ranged from -4 to +34 years. Although 14 patients presented OP after the onset of RA, two developed OP before RA and three developed OP simultaneously with RA. Patients receiving tumor necrosis factor inhibitors also developed OP. RA disease activity just before onset of OP was low in 8 of 14 RA cases. At the onset of OP, only two patients showed exacerbations of arthritis, whereas most patients presented with fever and serum C-reactive protein (CRP) elevations. Glucocorticoids were effective for OP in all patients who received them. Relapse occurred in 4 of 19 cases.OP develops in approximately 4% of RA patients, which occurs independently from arthritis activity and at any time in RA patients.

Formulation of rotational diffusion coefficient and the Stokes-Einstein-Debye (SED) relation is presented for diatomic molecular liquids by molecular dynamics simulation with two-center Lennard-Jones (2CLJ) potentials. Shear viscosity ηsv and rotational diffusion coefficient Dr are expressed as a function of molecular mass and number density N/V, or moment of inertia, packing fraction, temperature T, interaction energy, and molecular elongation l∗ ≡ l/σ, where N is the number of molecules included in the system volume V, l the bond length in the diatomic molecules, and σ the size parameter used in the LJ potentials. The packing fraction and elongation are the variables expressing molecular size and shape, respectively. These results produce directly a molecular-basis SED relation as Drηsv/T ∝ vm∗1/3l∗−3(N/V), where vm∗ is the dimensionless molecular volume expressed as an analytical function only of elongation l∗. That is, this SED equation depends not on the size but on the shape. This is highly contrasted with the original SED relation based on the size, which suggests overall reconsideration of the relation on a molecular scale. The shape term accounts for a paradox that more spherical molecules such as N2 deviate more strongly from the original SED equation based on a spherical particle. In addition, the SED relation without the size is consistent with the Stokes-Einstein relation for both the Lennard-Jones and 2CLJ liquids expressed as Dηsv/T ∝ (N/V)1/3, where D is the translational self-diffusion coefficient.

This study evaluates the physical properties of the molten salt Flinabe, using molecular dynamics simulations to discuss its applicability to a fusion blanket system. More specifically, the simulations calculate the density and viscosity of Flinabe to facilitate further discussion of the applicability from the viewpoint of the heat removal of the first wall. The results of the simulations are compared with data reported in earlier publications, which support the validity of the simulations. This study reveals that Flinabe tends to have lower viscosity than Flibe even when they contain almost the same BeF2. Analyzing the results of the simulations confirms that the degree of polymerization in Flinabe correlates with its viscosity, as that in Flibe does. The analyses also revealed, however, that the correlation in the case of Flibe is not directly applicable to the case of Flinabe.

A polarisable ion model is parameterised for the whole series of molten alkali halides by using first-principles calculations based on density functional theory. Viscosity, electrical conductivity and thermal conductivity are determined using molecular dynamics simulations via the Green–Kubo formulae and confronted to experimental results. The calculated transport coefficients are generally in much better agreement than those obtained with the empirical Fumi–Tosi potentials. The inclusion of polarisation effects significantly decreases the viscosity and thermal conductivity, while it increases the electrical conductivity. The individual dynamics of the ions is analysed using the Stokes–Einstein relation. The anion behaviour is always well represented using the slip boundary condition, while for cations there is an apparent shift from slip to stick condition when the ionic radius decreases. This difference is interpreted by subtle changes in their coordinating environment, which are maximised in the case o...

We studied the subsets of peripheral blood dendritic cells (DCs) and lipid accumulation in DCs to investigate the involvement of DCs in the decreased anticancer immunity of advanced lung cancer patients. We analyzed the population of DC subsets in peripheral blood using flow cytometry. We then determined lipid accumulation in the DCs using BODIPY 650/665, a fluorophore with an affinity for lipids. Compared with healthy controls, the number of DCs in the peripheral blood of treatment-naive cancer patients was significantly reduced. In patients with stage III + IV disease, the numbers of myeloid DCs (mDCs) and plasmacytoid DCs were also significantly reduced. Lipid accumulation in DCs evaluated based on the fluorescence intensity of BODIPY 650/665 was significantly higher in stage III + IV lung cancer patients than in the controls. In the subset analysis, the fluorescence was highest for mDCs. The intracellularly accumulated lipids were identified as triglycerides. A decreased mixed leukocyte reaction was observed in the mDCs from lung cancer patients compared with those from controls. Taken together, the results show that lung cancer patients have a notably decreased number of peripheral blood DCs and their function as antigen-presenting cells is decreased due to their high intracellular lipid accumulation. Thereby, anticancer immunity is suppressed.