Near-Infrared Electrochromic Behavior of Dibenzothiepin Derivatives Attached with Two Michler's Hydrol Blue Units.

10,11-Bis[bis(4-dimethylaminophenyl)methylene]dibenzo[bf]thiepin (1) and -oxepin (2) were prepared as stable yellow crystalline compounds, which are the cyclic analogues of electron-donating hexaarylbutadienes. Upon two-electron oxidation, they are reversibly transformed into the title dications (12+ and 22+ ) exhibiting near-infrared (NIR) absorptions, which were also isolated as stable salts. These redox pairs can serve as new entries into less well-explored organic NIR-electrochromic systems, and the separation of redox peaks (electrochemical bistability) was attained for 1/12+ and 2/22+ , thanks to drastic geometrical changes between neutral and dicationic states, as revealed by a series of X-ray analyses. Thiepin-S,S-dioxide analogue (3/32+ ) exhibits quite similar dynamic redox behavior due to nonaromatic nature of the dibenzothiepin and -oxepin unit in 12+ and 22+ , whereas the thiepin-S-oxide derivative (4/42+ ) does not exhibit bistability due to the smaller change in geometry upon electron transfer, showing that a subtle change of a bridging atom in the central seven-membered ring can modify the redox properties.

Hydrogen Bonding Propagated Phase Separation in Quasi-Epitaxial Single Crystals: A Pd-Br Molecular Insulator.

In condensed matter, phase separation is strongly related to ferroelasticity, ferroelectricity, ferromagnetism, electron correlation, and crystallography. These ferroics are important for nano-electronic devices such as non-volatile memory. However, the quantitative information regarding the lattice (atomic) structure at the border of phase separation is unclear in many cases. Thus, to design electronic devices at the molecular level, a quantitative electron-lattice relationship must be established. Herein, we elucidated a PdII-PdIV/PdIII-PdIII phase transition and phase separation mechanism for [Pd(cptn)2Br]Br2 (cptn = 1R,2R-diaminocyclopentane), propagated through a hydrogen-bonding network. Although the Pd···Pd distance was used to determine the electronic state, the differences in the Pd···Pd distance and the optical gap between Mott-Hubbard (MH) and charge-density-wave (CDW) states were only 0.012 Å and 0.17 eV, respectively. The N-H···Br···H-N hydrogen-bonding network functioned as a jack, adjusting the structural difference dynamically, and allowing visible ferroelastic phase transition/separation in a fluctuating N2 gas flow. Additionally, the effect of the phase separation on the spin susceptibility and electrical conductivity were clarified to represent the quasi-epitaxial crystals among CDW-MH states. These results indicate that the phase transitions and separations could be controlled via atomic and molecular level modifications, such as the addition of hydrogen bonding.

Metagenomic mining and structure-function studies of a hyper-thermostable cellobiohydrolase from hot spring sediment.

Enzymatic breakdown is an attractive cellulose utilisation method with a low environmental load. Its high temperature operation could promote saccharification and lower contamination risk. Here we report a hyper-thermostable cellobiohydrolase (CBH), named HmCel6A and its variant HmCel6A-3SNP that were isolated metagenomically from hot spring sediments and expressed in Escherichia coli. They are classified into glycoside hydrolases family 6 (GH6). HmCel6A-3SNP had three amino acid replacements to HmCel6A (P88S/L230F/F414S) and the optimum temperature at 95 °C, while HmCel6A did it at 75 °C. Crystal structure showed conserved features among GH6, a (ß/α)8-barrel core and catalytic residues, and resembles TfCel6B, a bacterial CBH II of Thermobifida fusca, that had optimum temperature at 60 °C. From structure-function studies, we discuss unique structural features that allow the enzyme to reach its high thermostability level, such as abundance of hydrophobic and charge-charge interactions, characteristic metal bindings and disulphide bonds. Moreover, structure and surface plasmon resonance analysis with oligosaccharides suggested that the contribution of an additional tryptophan located at the tunnel entrance could aid in substrate recognition and thermostability. These results may help to design efficient enzymes and saccharification methods for cellulose working at high temperatures.

Changing the structural and physical properties of 3-arm star poly(δ-valerolactone)s by a branch-point design.

The chemical structure of a branch point of star-shaped polymers has been considered to have a small influence on the physical properties of the entire polymer. Contrary to this general notion, here we show that a 3-arm star polymer, composed of three poly(δ-valerolactone) arms extended from one side of a triptycene branch point, exhibits a remarkably high complex viscosity, compared to the analogous star-shaped polymers with a branch point of a triptycene isomer or triphenylethane.

Mechanism of Elastic Properties of Biodegradable Poly[(R)-3-Hydroxybutyrate-co-4-hydroxybutyrate] Films Revealed by Synchrotron Radiation.

Reversible elastic films of biobased and biodegradable poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate] [P(3HB-co-4HB)] were prepared by uniaxial drawing procedures. Mechanical properties and highly ordered film structures were investigated by tensile testing and both static-state and in situ wide-angle X-ray diffraction and small-angle X-ray scattering with synchrotron radiation during stretching and relaxing. Despite the crystalline nature of the polymers, the elongation at break of these films was greater than 1500%. Reversible elasticity was achieved after the first 10 times of uniaxial stretching. X-ray measurement results indicated that on stretching, ß-form molecular chains with a planar zigzag conformation were introduced from molecular chains with random coils in the amorphous regions between α-form lamellar crystals. Notably, the orientation of the α-form lamellar crystals increased after relaxation of the molecular chains with a planar zigzag conformation (ß-form) between the lamellar crystals (α-form). Reversible elastic properties were regenerated by a planar zigzag conformation between the lamellar crystals, the extension of molecular chains in lamellar crystals by the rotation of molecular conformation, and changes in the degree of orientation of the lamellar crystals.

Bilateral oculomotor nerve palsy in a case of anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder.

Neuromyelitis optica spectrum disorder (NMOSD) has a wide disease spectrum and sometimes shows abnormal eye movement with brainstem manifestations. However, bilateral oculomotor nerve palsy with a midbrain lesion has never been reported in a patient with NMOSD. We describe a 61-year-old woman with progressive ptosis and diplopia. She displayed bilateral oculomotor nerve palsy and hypersomnia. Brain MRI demonstrated abnormal signal intensities in the midbrain and around the third ventricle and hypothalamus with a mild contrast enhancement. A cerebrospinal fluid study indicated elevated protein and pleocytosis. Because serum anti-aquaporin-4 IgG antibody was positive, the patient was diagnosed with neuromyelitis optica spectrum disorder with aquaporin-4 IgG. We report for the first time bilateral oculomotor nerve palsy as an initial manifestation in a patient with aquaporin-4 positive NMOSD.

Pretreatment Blood Pressure is a Simple Predictor of Hemorrhagic Infarction after Intravenous Recombinant Tissue Plasminogen Activator (rt-PA) Therapy.

BACKGROUND: Hemorrhagic infarction (HI) is among the most severe complications that can occur following the administration of intravenous recombinant tissue plasminogen activator (rt-PA). In the present study, we aimed to determine the optimal cut-off points of blood pressure (BP) for HI after rt-PA treatment, and to compare our findings with those for other prediction models. METHODS: We analyzed data from 109 consecutive patients with stroke treated at our hospital between 2009 and 2016. HI was confirmed via computed tomography or magnetic resonance imaging. Patients were classified into a symptomatic HI group, an asymptomatic HI group, and a non-HI group. BP was measured on admission and before rt-PA treatment. Glucose Race Age Sex Pressure Stroke Severity (GRASPS) and Totaled Health Risks in Vascular Events (THRIVE) scores were also calculated. Receiver operating characteristic (ROC) analysis was used to determine factors associated with symptomatic and asymptomatic HI. RESULTS: Among the 109 total patients, 25 patients developed symptomatic HI, while 22 patients developed asymptomatic HI. ROC analysis for predicting symptomatic and asymptomatic HI revealed that the area under the curve for pretreatment systolic BP (SBP) was .88 (95% confidence interval[CI]: .83-.94), while those for GRASPS and THRIVE scores were .75 (95% CI: .66-.85) and .69 (95% CI: .59-.79), respectively. We identified an optimal cut-off point of 160 mm Hg (sensitivity: 82.3%; specificity: 76.6%; diagnostic accuracy: 80.0%; positive predictive value: 76.6%; negative predictive value: 82.5%). CONCLUSIONS: Pre-treatment SBP may be a simple predictor of symptomatic and asymptomatic HI in patients with stroke undergoing rt-PA treatment.

Chiral crystal-like droplets displaying unidirectional rotational sliding.

The self-assembly of organic molecules into supramolecular materials with structural ordering beyond the nanometre scale is challenging. Here, we report the spontaneous self-assembly of a chiral discotic triphenylene derivative into millimetre-sized droplets. The structure of the droplets is characterized by high positional and orientational ordering and a three-dimensional integrity similar to that of single crystals. Notwithstanding, these assemblies slide when placed on a vertical substrate demonstrating their fluid nature. X-ray imaging shows that during the sliding process the internal crystal-like structure is maintained and that the droplets undergo clockwise or counterclockwise unidirectional rotation, depending on the chirality of their molecular components. Rheological measurements suggest that this rotational behaviour might result from the distinct yield stress between the (R)- and (S)-enantiomers. Overall, our findings demonstrate that molecular chirality can determine the movement direction of a supramolecular structure, thus expanding the fundamental understanding of the structure and dynamics of soft materials.

In Situ Tracking of Dynamic NO Capture through a Crystal-to-Crystal Transformation from a Gate-Open-Type Chain Porous Coordination Polymer to a NO-Adducted Discrete Isomer.

Optimal control of gas adsorption properties in metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) remains a great challenge in the field of materials science. An efficient strategy to capture electron-acceptor-type gas molecules such as nitrogen monooxide (NO) is to use host-guest interactions by utilizing electron-donor-type MOFs/PCPs as host frameworks. Herein, we focus on a highly electron-donating chain compound by using the paddlewheel-type [Ru2 II,II ] complex [Ru2 (2,4,5-Me3 PhCO2 )4 ] (2,4,5-Me3 PhCO2 - =2,4,5-trimethylbenzoate) with the phenazine (phz) linker: [Ru2 (2,4,5-Me3 PhCO2 )4 (phz)] (1). Compound 1 exhibited a specific gated adsorption for NO under gas pressures greater than 60 kPa at 121 K, which finally resulted in approximately seven molar equivalents being taken up at 100 kPa followed by four molar equivalents remaining under vacuum at 121 K; its Rh isomorph (2) with weaker donation ability was inactive for NO. When the sample of 1⊃4 NO was heated to room temperature, the compound underwent a crystal-to-crystal phase transition to give [Ru2 (2,4,5-Me3 PhCO2 )4 (NO)2 ](phz) (1-NO), involving a post-synthetic nitrosylation on the [Ru2 ] unit, accompanied by an eventful site-exchange with phz. This drastic event, which is dependent on the NO pressure, temperature, and time, was coherently monitored by using several different in situ techniques, revealing that the stabilization of NO molecules in nanosized pores dynamically and stepwisely occurred with the support of strong electronic/magnetic host-guest interactions.

Terminal Functionalization with a Triptycene Motif That Dramatically Changes the Structural and Physical Properties of an Amorphous Polymer.

A surprising terminal-group effect on the structural and physical properties of an amorphous polymer is reported. We recently demonstrated that triptycene derivatives with substituents at the 1,8,13-positions show specific self-assembly behavior, enabling the formation of a well-defined "2D + 1D" structure based on nested hexagonal packing of the triptycenes. Upon terminal functionalization with a 1,8-substituted triptycene (1,8-Trip), a liquid polymer, polydimethylsiloxane (PDMS, Mn = 18-24 kDa), turned into a highly viscous solid that exhibits birefringence at 25 °C. Small-angle and wide-angle X-ray scattering measurements revealed that the resulting telechelic PDMS assembles into a 2D + 1D structure, where layers of PDMS domains, formed between 2D assemblies of the triptycene termini, stack into a 1D multilayer structure with a layer spacing of 18-20 nm. Because of this structuring, the complex viscosity of the telechelic PDMS was dramatically enhanced, providing a value 4 orders of magnitude greater than that of the original PDMS. Remarkably, the structural and physical properties of PDMS were hardly changed upon terminal functionalization with another regioisomer of triptycene (1,4-Trip), which differs only in the substitution pattern.

Rewriting the phase diagram of a diamagnetic liquid crystal by a magnetic field.

Magnetic fields have been considered to only interact with organic materials non-destructively, leaving their fundamental structures unaffected, even when a strong magnetic field generated from a superconducting magnet is applied. Here we report an unprecedented observation that a liquid-crystalline mesophase of a diamagnetic molecular assembly with an orthorhombic or a cubic structure is formed selectively in the absence or presence of a strong magnetic field. The constituent molecule is a triphenylene derivative carrying six imidazolium bromide-terminated alkyl side chains and exhibits a cubic, orthorhombic, or hexagonal columnar mesophase when complexed with an appropriate amount of lanthanum(III) bromide. Thermal processing of the La3+-containing liquid-crystalline assembly in the presence of a 10-tesla magnetic field resulted in a phase diagram, in which the orthorhombic phase is completely replaced with the cubic phase. The discovery of this magneto-induced phase-selection offers an insight into the interactions between magnetic fields and organic material.

High-Density Lipoprotein Subclasses and Mild Cognitive Impairment: Study of Outcome and aPolipoproteins in Dementia (STOP-Dementia)1.

BACKGROUND: High-density lipoprotein (HDL) containing apolipoprotein A-I is associated with the pathogenesis of Alzheimer's disease (AD). HDL particle size is modified in the presence of pathological conditions, while the significance of the HDL particle size remains controversial. OBJECTIVE: The aim of this study was to investigate the HDL lipoprotein subclasses in mild cognitive impairment (MCI) and AD. METHODS: This cross-sectional study included 20 AD patients, 17 MCI patients, and 17 age-matched controls without cognitive impairment, selected from the database of the Study of Outcome and aPolipoproteins in Dementia (STOP-Dementia) registry. The diagnoses of AD and MCI were performed by expert neurologists according to the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition criteria. Serum HDL subclasses were measured by electrophoretic separation of lipoproteins using the Lipoprint System. The neutrophil-lymphocyte ratio (NLR), a marker of inflammation, was calculated by dividing the neutrophil count by the lymphocyte count. RESULTS: Small-sized HDL particle levels in the MCI group were significantly higher than in the control group, although there was no difference in serum HDL-cholesterol levels between MCI and control groups. NLR in the MCI group was higher than in the control group, but this difference was non-significant (p = 0.09). There was no difference in HDL subclasses or NLR between the AD and control groups. CONCLUSION: These findings suggest that HDL subclasses might be associated with the development of MCI.

Predictors of Cardioembolic Stroke in Japanese Patients with Atrial Fibrillation in the Fushimi AF Registry.

BACKGROUND: Large-scale clinical trials have analyzed risk factors for any ischemic stroke in patients with atrial fibrillation (AF). However, the risk factors for cardioembolic stroke (CES), specifically, have not been reported. To clarify the risk factors for CES and clinically significant cardioembolic infarction, we examined the incidence of CES and larger infarct volume (IV) (> 30 mL) CES, employing the Fushimi AF Registry, a community-based prospective cohort of AF patients in the Fushimi ward, Kyoto, Japan. METHODS: A total of 4,182 Fushimi AF patients were enrolled from March 2011 to December 2014. The risk factors for CES were evaluated using multivariate analysis. RESULTS: Of 4,182 patients enrolled, 3,749 patients were observed for ≥1 year. During the follow-up period (mean duration, 979 ± 7.7 days), 91/3,749 patients experienced a CES (2.43%). Significant risk factors associated with CES were older age (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.01-1.72; p = 0.046), low body weight (OR, 1.30; 95% CI, 1.03-1.65; p = 0.033), sustained AF (OR, 1.67; 95% CI, 1.05-2.71; p = 0.034), and previous stroke or transient ischemic attack (TIA) (OR, 1.94; 95% CI, 1.22-3.06; p = 0.004). Predictors of a large IV were chronic kidney disease (CKD) (OR, 2.08; 95% CI, 1.09-4.05; p = 0.027) and previous stroke/TIA (OR, 2.27; 95% CI, 1.19-4.24; p = 0.011). CONCLUSIONS: In this population-based cohort of Japanese patients with AF, in addition to previous stroke/TIA and older age, sustained AF and low body weight emerged as risk factors for CES, as opposed to any stroke, which may have a different risk profile. Patients with CKD or previous stroke/TIA who developed cardioembolic infarction exhibited more advanced severity. There is a need for direct oral anticoagulants that can be used safely in patients with comorbid AF and CKD.

Optical and Structural Properties of ESIPT Inspired HBT-Fluorene Molecular Aggregates and Liquid Crystals.

In bulk materials, positional isomers not only help in understanding how slight difference in molecular structure alters the crystal packing and optical properties, but also play a key role in developing new type of materials for functional applications. A detailed study on the photophysical properties of fluorene-HBT positional isomers in solution and in the solid state providing a molecular level understanding of the factors which influence fluorescence behavior is reported. Two molecules Ia and IIa were synthesized by Suzuki coupling reaction and their photophysical properties were compared to positional isomers Ib and IIb. Crystal structure analyses and density functional theory (DFT) computation studies were performed to understand structure-properties relation and the results reveal that changing substitution pattern has a marked influence on their packing modes and luminescence properties. Strong noncovalent interactions (π-π) in the solid state hamper the excited state intramolecular proton transfer (ESIPT) process which causes fluorescence quenching in the solid state (Ia and IIa = Φf, 28-40%; Ib and IIb = Φf, 55-67%). Compounds show solvent-responsive and aggregation induced emission (AIE) properties. Bent structures of Ia with double and symmetric substitution of ESIPT motifs exhibit particularly unique condensed phase upon heating, confirmed as a nematic liquid crystalline phase, and this is the first report on the ESIPT and AIE active liquid crystalline materials with a banana-shaped molecule.

Successive Dimensional Transition in (TMTTF)_{2}PF_{6} Revealed by Synchrotron X-ray Diffraction.

A quasi-one-dimensional organic charge-transfer salt (TMTTF)_{2}PF_{6} undergoes a multistep phase transition as the temperature decreases. One of these transitions is called a "structureless transition," and these detailed structures were unknown for many years. With synchrotron x-ray diffraction, we observed a slight structural difference owing to the effect of charge-order transition between two TMTTF molecules in a dimer, which corresponds to the charge transfer δ_{CO}=0.20e. The two-dimensional Wigner crystallization was determined from an electron density analysis using core differential Fourier synthesis. Furthermore, we found that the ground state due to tetramerization, called the spin Peierls phase, is a three-dimensional transition with interchain correlation.

Visualization of Individual Images in Patterned Organic-Inorganic Multilayers Using GISAXS-CT.

Using grazing-incidence small-angle scattering (GISAXS) with computed tomography (CT), we have individually reconstructed the spatial distribution of a thin gold (Au) layer buried under a thin poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) layer. Owing to the difference between total reflection angles of Au and PS-b-P2VP, the scattering profiles for Au nanoparticles and self-assembled nanostructures of PS-b-P2VP could be independently obtained by changing the X-ray angle of incidence. Reconstruction of scattering profiles allows one to separately characterize spatial distributions in Au and PS-b-P2VP nanostructures.

Detailed Structural Analysis of a Self-Assembled Vesicular Amphiphilic NCN-Pincer Palladium Complex by Using Wide-Angle X-Ray Scattering and Molecular Dynamics Calculations.

Wide-angle X-ray scattering experiments and all-atomistic molecular dynamics calculations were performed to elucidate the detailed structure of bilayer vesicles constructed by self-assembly of an amphiphilic palladium NCN-pincer complex. We found an excellent agreement between the experimental and calculated X-ray spectra, and between the membrane thickness determined from a TEM image and that calculated from an electron-density profile, which indicated that the calculated structure was highly reliable. The analysis of the simulated bilayer structure showed that in general the membrane was softer than other phospholipid bilayer membranes. In this bilayer assemblage, the degree of alignment of complex molecules in the bilayer membrane was quite low. An analysis of the electron-density profile shows that the bilayer assemblage contains a space through which organic molecules can exit. Furthermore, the catalytically active center is near this space and is easily accessible by organic molecules, which permits the bilayer membrane to act as a nanoreactor. The free energy of permeation of water through the bilayer membrane of the amphiphilic complex was 12 kJ mol-1 , which is much lower than that for phospholipid bilayer membranes in general. Organic molecules are expected to pass though the bilayer membrane. The self-assembled vesicles were shown to be catalytically active in a Miyaura-Michael reaction in water.

First-Principles Calculation, Synthesis, and Catalytic Properties of Rh-Cu Alloy Nanoparticles.

The first synthesis of pure Rh1-x Cux solid-solution nanoparticles is reported. In contrast to the bulk state, the solid-solution phase was stable up to 750 °C. Based on facile density-functional calculations, we made a prediction that the catalytic activity of Rh1-x Cux can be maintained even with 50 at % replacement of Rh with Cu. The prediction was confirmed for the catalytic activities on CO and NOx conversions.

Regulation of NO Uptake in Flexible Ru Dimer Chain Compounds with Highly Electron Donating Dopants.

On-demand design of porous frameworks for selective capture of specific gas molecules, including toxic gas molecules such as nitric oxide (NO), is a very important theme in the research field of molecular porous materials. Herein, we report the achievement of highly selective NO adsorption through chemical doping in a framework (i.e., solid solution approach): the highly electron donating unit [Ru2(o-OMePhCO2)4] (o-OMePhCO2- = o-anisate) was transplanted into the structurally flexible chain framework [Ru2(4-Cl-2-OMePhCO2)4(phz)] (0; 4-Cl-2-OMePhCO2- = 4-chloro-o-anisate and phz = phenazine) to obtain a series of doped compounds, [{Ru2(4-Cl-2-OMePhCO2)4}1-x{Ru2(o-OMePhCO2)4}x(phz)] (x = 0.34, 0.44, 0.52, 0.70, 0.81, 0.87), with [Ru2(o-OMePhCO2)4(phz)] (1) as x = 1. The original compound 1 was made purely from a "highly electron donating unit" but had no adsorption capability for gases because of its nonporosity. Meanwhile, the partial transplant of the electronically advantageous [Ru2(o-OMePhCO2)4] unit with x = 0.34-0.52 in 0 successfully enhanced the selective adsorption capability of NO in an identical structurally flexible framework; an uptake at 95 kPa that was 1.7-3 mol/[Ru2] unit higher than that of the original 0 compound was achieved (121 K). The solid solution approach is an efficient means of designing purposeful porous frameworks.

Thermodynamically Anchoring-Frustrated Surface to Trigger Bulk Discontinuous Orientational Transition.

Surface-specific liquid crystal (LC) nanostructures provide a unique platform for studying surface-wetting phenomena and also for technological applications. The most important studies on LC properties are related to bulk alignment, surface anchoring, and so on. Here, we study an LC system with a nematic liquid crystal (NLC) on a perfluoropolymer-coated substrate, in which a discontinuous bulk orientational transition has recently been found. Using free-energy analysis based on experimental results of the newly-conducted grazing-incidence X-ray diffraction (GI-XRD) measurements, we have confirmed a thermodynamic growth process of smectic liquid crystalline wetting nanosheets on the surface and successfully explained that a frustrated surface of planar and vertical anchoring states accompanied by an elastic energy cost kinetically triggers the bulk reorientation in the first-order manner. This interfacial bottom-up process may offer a general insight into how interfacial hierarchical molecular architectures alter the bulk properties of matter thermodynamically.