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6-Dimethylamino-2-phenylbenzothiazole ( 1a ) mimicking the firefly oxyluciferin structure and the derivatives with an electron-withdrawing substituent on the phenyl group were prepared, and their fluorescence properties were investigated in various solvents. 1a showed solvatochromic fluorescence with good fluorescence quantum yields ( Φ f >0.8). The introduction of an electron-withdrawing group led to a red-shift of the emission maximum. In particular, the derivatives with the 2,2-dicyanoethenyl and (1,3-dihydro-1,3-dioxo-2 H -inden-2-ylidene)methyl groups showed near-infrared fluorescence in chloroform. In addition, the derivative with the phenylimine moiety showed efficient solid-state fluorescence, resulted from a molecular arrangement inhibiting intermolecular interactions for quenching the fluorescence state in crystals. [ABSTRACT FROM AUTHOR]

Abstract: A phase field modelling to clarify the multi-scale deformation mechanism of polycrystalline metals was undertaken. Modified coupling equations between the phase and stress/strain using a multiphase field model were introduced, and solved numerically under typical test-case conditions. The grain growth process was simulated first, and the microscopic stress distribution was calculated. The microstructural morphology was drastically affected by the stress dependency. The relationship between macroscopic loading and microstructure was then verified by a tensile test. Microstructural rearrangement was induced by macroscopic deformation, and we conclude that the present model is effective for further investigation into the multi-scale deformation mechanics. [Copyright &y& Elsevier]

Abstract: The stability of grain boundaries (GBs) and the dynamic behavior of atoms in the boundary region are investigated from an atomistic standpoint. Symmetric and non-symmetric GBs are constructed using an fcc configuration, and the GB energy is calculated as a function of the misorientation angles using a Lennard-Jones-type interatomic potential. Several specific angles are revealed to exhibit cusp-shaped low values. The effect of atomic relaxation at the GB is then simulated, showing a decrease in the GB energy. Changes in the morphology of a grain embedded in a bulk single crystal are also simulated. Using both a square-grain and a circular-grain model, the following results are obtained. In models with small misorientation angles, the grain changes orientation and the GB vanishes. When the orientations are initially stable, no change in the grain is observed. However, in models with non-stable orientations, local stabilization occurs by a rearrangement of the atoms around the GB, and the shape of the grain is transformed. Finally, a similar simulation is carried out at a high temperature, and this reveals that grain contraction occurs even in models that are stable at a low temperature, and that the grain eventually disappears. [Copyright &y& Elsevier]

We performed daily cone-beam computed tomography (CBCT) to determine the impact of rectal gas on the movements of prostate and seminal vesicles (SVs). We aimed to determine the relationship between planning target volume (PTV) margins and rectal gas. In 30 treatments of 15 prostate cancer patients, excessive rectal gas was removed and CBCT images were analyzed. Image registration between planning CT and daily CBCT images before and after rectal gas removal was performed for pelvic bone and prostate matching. The couch movement distance between each matching was considered the prostate movement. In addition, we measured SV tip movement between each matching. The anterior–posterior movement of the prostate before rectal gas removal (3.1 ± 2.9 mm) was significantly greater than that after rectal gas removal (1.2 ± 1.2 mm; p < 0.01). The left–right and superior–inferior movements were similar regardless of the presence or absence of rectal gas. The SV movement distances before and after rectal gas removal were 11.0 ± 5.8 mm and 4.6 ± 3.8 mm, respectively (p < 0.01), in pelvic bone matching, and 8.0 ± 4.2 mm and 3.8 ± 3.2 mm, respectively (p < 0.01), in prostate matching. After rectal gas removal, the SV position did not differ significantly between each matching. In 26 of the 30 treatments, SV movement distance in the presence of rectal gas was >6 mm, which is the minimum PTV margin at our institution. In comparison, after rectal gas removal and prostate matching, only 6 treatments demonstrated an SV movement distance of >6 mm. In the presence of rectal gas, the SVs require greater PTV margins than the prostate. Rectal gas removal should be considered if the movement distance on prostate matching is greater than the minimum PTV margin at treating institution. [ABSTRACT FROM AUTHOR]

Abstract: Stress evolution during solidification is simulated by using the phase field model. The coupling equations for phase transformation, temperature and stress/strain are derived based on thermo-dynamical theory including elastic strain energy, which is summarized as follows: phase transformation is governed by the phase field equation in which not only temperature but also stress are introduced as parameters. In the heat conduction equation, the effect of latent heat generation due to phase change and the heat generation due to mechanical work are taken into account. The volumetric change associated with temperature variation and phase transformation is expressed in the constitutive equation, while, in this paper, the stress or flow in liquid is neglected for simplicity. In order to verify the efficiency of these equations, numerical simulations are carried out by using a simple model of the finite element method. The effects of transformation expansion coefficient for two cases of dilatation and contraction are simulated, and qualitatively adequate results are presented. [Copyright &y& Elsevier]

Abstract: In this study, we investigated the influence of base resin and curing agent and their mixture on the curing characteristics by performing experiments and molecular simulations. In the curing experiment of epoxy resin, we used differential scanning calorimetry (DSC) to obtain the conversion by mixing curing agents and base resins. We used the molecular orbital method (MO) and the molecular dynamics method (MD) to simulate the curing reaction in molecular scale and investigate the effect of differences in resin composition on the curing characteristics. This simulation took into consideration activation energy, heat of formation, and polarization in the curing reaction. The simulation captures the trend of curing reaction obtained by the experiment. We found that the selection and mixture of curing agents are very important when controlling the curing characteristics of epoxy resin. [Copyright &y& Elsevier]