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Variations in the molecular aggregation structures and optical properties of a semialiphatic fluorinated 10FEDA/ DCHM (poly(4,4′-diaminocyclohexylmethane 1,4-bis(3,4-dicarboxytrifluorophenoxy) tetrafluorobenzeneimide) polyimide (PI), which exhibits strong cyan fluorescence, were examined under very high pressure up to 8 GPa using synchrotron wide-angle X-ray diffraction (WAXD) and fluorescence spectroscopy. The fluorescence intensity of a PI film imidized at 220 °C was significantly reduced by applying pressure up to 1 GPa, which should be due to an appreciable reduction in interchain free volume, as indicated by a decrease in the d-spacing values of WAXD peaks which correspond to intermolecular ordering. In contrast, a PI film imidized at 300 °C, which exhibited weaker fluorescence than that imidized at 220 °C at atmospheric pressure, demonstrated a much smaller reduction in fluorescence intensity below 1 GPa. Such differences in pressure dependence clearly reflect the degrees of PI chain packing formed at different imidization temperatures. These phenomena induced by high pressure were almost reversible between pre-and postpressurization states with small hysteresis in the WAXD patterns and fluorescence spectra.

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The relationships between the molecular structure, polymer chain orientation, β‐transition temperature, and the coefficients of in‐plane and out‐of‐plane linear thermal expansions (CTE, α), as well as the coefficients of volumetric thermal expansion (CVE, β), are extensively examined for ten types of self‐standing aromatic polyimide (PI) films via thermomechanical analysis, near‐infrared optical interferometry, and dynamic mechanical analysis. The out‐of‐plane CTEs (α⊥) of PI films having rigid‐rod structures are 20–40 times larger than their in‐plane CTEs (α//), whereas the α⊥ values of PI films having bent linkages in the main chains are comparable to their α// values. In addition, the values of normalized anisotropy in CTE for PIs (η), defined as (α⊥ −α//)/β, are proportional to the orientation coefficients (P200) estimated from the in‐plane/out‐of‐plane birefringence (Δn) and molecular polarizability tensor. Furthermore, larger CVE values are observed for PIs exhibiting lower β‐relaxation temperatures (Tβ), at which localized molecular motion occurs. In contrast, smaller CVE values are observed for PIs exhibiting higher Tβs because their local molecular motions are suppressed due to the structural rigidity and dense molecular packing.

The ongoing structure of radiation oncology in Japan in terms of equipment, personnel, patient load and geographic distribution was evaluated in order to radiation identify and improve any deficiencies. A questionnaire-based national structure survey was conducted from March 2010 to January 2011 by the Japanese Society for Therapeutic Radiology and Oncology (JASTRO). These data were analyzed in terms of the institutional stratification of the Patterns of Care Study (PCS). The total numbers of new cancer patients and total of cancer patients (new and repeat) treated with radiation in 2009 were estimated at 201,000 and 240,000, respectively. The type and numbers of systems in actual use consisted of Linac (816), telecobalt (9), Gamma Knife (46), 60 Co remote afterloading system (RALS) (29) and 192 Ir RALS systems (130). The Linac systems used dual energy function for 586 (71.8%), 3DCRT for 663 (81.3%) and IMRT for 337 units (41.3%). There were 529 JASTRO-certified radiation oncologists (ROs), 939.4 full-time equivalent (FTE) ROs, 113.1 FTE medical physicists and 1836 FTE radiation therapists. The frequency of interstitial radiation therapy use for prostate and of intensity-modulated radiotherapy increased significantly. PCS stratification can clearly identify the maturity of structures based on their academic nature and caseload. Geographically, the more JASTRO-certified physicians there were in a given area, the more radiation therapy tended to be used for cancer patients. In conclusion, the Japanese structure has clearly improved during the past 19 years in terms of equipment and its use, although a shortage of manpower and variations in maturity disclosed by PCS stratification remained problematic in 2009.