Soft Crystals: Flexible Response Systems with High Structural Order

A new material concept of soft crystals is proposed. Soft crystals respond to gentle stimuli such as vapor exposure and rubbing but maintain their structural order and exhibit remarkable visual changes in their shape, color, and luminescence. Various interesting examples of soft crystals are introduced in the article. By exploring the interesting formation and phase-transition phenomena of soft crystals through interdisciplinary collaboration, new materials having both the characteristics of ordered hard crystals and those of flexible soft matter are expected.     

Triphenylsilane‐fused Porphyrins

A reaction sequence of 2‐(diphenylsilyl)phenylation by Negishi coupling and intramolecular sila‐Friedel–Crafts reaction has been explored for the synthesis of mono‐triphenylsilane‐fused porphyrins 5 M and 6 M (M= Ni, Zn) and bis‐triphenylsilane‐fused porphyrins 7 M and 8 Ni . A triply linked triphenylsilane‐fused Ni^II porphyrin, 13 Ni , was synthesized in a stepwise manner involving the above reaction sequence and a final Pd‐catalyzed C?H activating arylative cyclization. The silicon atom in 13 Ni takes a distorted planarized structure with an almost perpendicular Si‐phenyl group, causing an electronic effect due to effective σ*–π* interaction.     

Electron transport and electrochemistry of mesomorphic fullerenes with long-range ordered lamellae

Fullerenes, C60, modified with long alkyl chains form long-range ordered lamellar mesophases permitting a high C60 content. The mesomorphic fullerenes feature reversible electrochemistry and a comparably high electron carrier mobility making them attractive components for fullerene-based soft materials.     

A nanocarbon film electrode as a platform for exploring DNA methylation

We describe the quantitative nonlabel electrochemical detection of both cytosine (C) and methylcytosine (mC) in oligonucleotides using newly developed nanocarbon film electrodes. The film consists of nanocrystalline sp2 and sp3 mixed bonds formed by employing the electron cyclotron resonance (ECR) sputtering method. We successfully used this film to develop a simple electrochemical DNA methylation analysis technique based on the measurement of the differences between the oxidation currents of C and mC since our ECR nanocarbon film electrode can directly measure all DNA bases more quantitatively than conventional glassy carbon or boron-doped diamond electrodes. The excellent properties of ECR nanocarbon film electrodes result from the fact that they have a wide potential window while maintaining the high electrode activity needed to oxidize oligonucleotides electrochemically. Proof-of-concept experiments were performed with synthetic oligonucleotides including different numbers of C and mC. This film allowed us to perform both C- and mC-positive assays solely by using the electrochemical oxidation of oligonucleotides without bisulfite or labeling processes.     

Ion heating by lower hybrid waves

An ion heating by excited lower hybrid waves has been observed in a coaxial type double plasma device. The lower hybrid resonance heating is examined on the two components of the kinetic energy perpendicular and parallel to the magnetic field.     

Prediction of early response to radiotherapy of uterine carcinoma with dynamic contrast-enhanced MR imaging using pixel analysis of MR perfusion imaging

Purpose

To assess the predictability of the response to radiotherapy of uterine carcinoma, this study retrospectively analyzed dynamic contrast-enhanced magnetic resonance images (DCE-MRI) taken before radiotherapy.

Materials and Methods

Forty-two patients with uterine carcinoma were studied, of whom 22 had adenocarcinoma and 20 had squamous cell carcinoma (SCC). In DCE-MRI analysis, two parameters, SIe and R_down, were measured. SIe is a median value for the degree of signal intensity change in all selected pixels in the tumor at 1–2 min after contrast agent injection. R_down is the ratio of the number of down-sloped pixels to that of all selected pixels 3–7 min after injection. The tumor volume reduction rate (TVRR) was measured by MRI-based volumetry in pre- and post-radiotherapy transverse T2-weighted images.

Results

Overall, TVRR was significantly correlated to both SIe (r=0.37, P=.015) and R_down (r=0.73, P<.0001). In the separate patient groups, SIe but not R_down was significantly different between the adenocarcinoma and SCC patients (t=3.64, P<.001). TVRR was not correlated to SIe in any group. TVRR was significantly correlated to R_down in adenocarcinoma patients (r=0.78, P<.001) but not in SCC patients.

Conclusion

SIe may reflect differences in histological characteristics. R_down may be useful for predicting the response to radiotherapy of uterine carcinoma.     

Structure and piezoelectric properties of 1-μm-thick polar-axis-oriented CaBi<Subscript>4</Subscript>Ti<Subscript>4</Subscript>O<Subscript>15</Subscript> films

1-μm-thick polar-axis-oriented CaBi₄Ti₄O₁₅ (CBTi144) films were fabricated by control of nucleation and growth in alkoxy-derived non-crystalline layers on Pt foils. The oxygen ambient during pre-baking impacted both the cross-sectional microstructure and the crystallographic orientation. The 1-μm-thick film showed relatively high intensities of (100)/(010) diffraction lines in the X-ray diffraction profile and simultaneously had a closely packed dense structure in the transmission electron microscopy cross-sectional profile. Resultantly, the leakage current density decreased to about 7×10^-8 A/cm² at 10 V. The piezoelectric constant d₃₃ was determined to be 260 pm/V at a maximum poling voltage of 60 V by measurements using piezoelectric force microscopy. PACS 77.55.+f; 77.84.-s; 77.65.-j; 68.55.Jk     

On a new geometric constant related to the modulus of smoothness of a Banach space

We shall introduce a new geometric constant A(X) of a Banach space X,which is closely related to the modulus of smoothness ρX(τ),and investigate it in relation with the constant A2(X) by Baronti et al.,the von Neumann–Jordan constant CNJ(X) and the James constant J(X).A sequence of recent results on these constants as well as some other geometric constants will be strengthened and improved.     

Finite temperature neutral-ionic transition and lattice dimerization in charge-transfer complexes: QMC study

We numerically investigate the neutral-ionic (NI) phase transition on the basis of the ionic extended Hubbard model with electron-lattice coupling as well as inter-chain Coulomb interaction. Finite-temperature (T) phase transitions are examined by a quantum Monte Carlo method, within adiabatic approximation for the lattice displacement together with inter-chain mean-field treatment. The NI transition either with or without the electron-lattice coupling is of first-order at low-T and transforms into a cross-over regime with increasing T. We confirm there exist two phases in the ionic region: with and without lattice dimerization, as suggested in recent experiments. The former is ferroelectric, which is rooted in the Coulomb interactions and a spin-Peierls mechanism.