[en] Definitive radiation therapy (RT) in 52 patients with the inoperable esophageal cancer was retrospectively evaluated with regard to irradiation field and combined chemotherapy. Treatments were divided into RT alone (n=19), RT with low-dose cisplatin (CDDP) (n=25), and RT with intermediate-dose CDDP group (n=8). Although initial recurrences were commonly observed in the primary sites, there were out-field lymph node failures in three patients with stage II disease, three with stage III, and one with stage IVa. Two-years cause specific survival rates of stage 0/I, II, III, and IVa were 100%, 64%, 14%, and 18% respectively. In 42 patients with II-IVa stages, the significant prognostic factors were performance status and clinical stage. Combined chemotherapy did not contribute significant improvement of survival rates for the inoperable esophageal cancer. Prophylactic irradiation for the lymph node metastases should be considered for patients with stage II and III diseases. (author)

[en] We evaluated the clinical efficacy of transcatheter arterial embolization (TAE) for the management of retroperitoneal bleeding in a case of pelvic fracture. A retrospective review of 206 patients with pelvic fractures was performed. Thirty-four patients who were hemodynamically unstable or had evidence of ongoing hemorrhage required TAE. Rescue rate, effective rate, and mortality rate among the patients with multiple organ injuries were calculated. Charts were reviewed for age, Japanese coma scale (JCS), hemoglobin, blood pressures, extent of retroperitoneal hemorrhage, pelvic fracture pattern/extent of embolization, and time from judging indication of TAE to angiography. Data of patients who died of pelvic fracture hemorrhage was compared with that of others. Statistical analysis was done with analysis of variance, and the two groups were compared using Student's t-test. Rescue rate, success rate, and mortality rate were 76% (26/34), 91% (31/34), and 33% (8/24), respectively. Only JCS reached statistical significance. The complications of gluteal skin and muscle necrosis were experienced in one patient. Two patients with lung contusion and one patient who had suffered from idiopathic interstitial pneumonia died from disseminated intravascular coagulation associated with pneumonia. Viscorectal dysfunctions, which were observed in ten patients, were considered to be independent of TAE. TAE for pelvic fracture hemorrhage was considered effective. Complications of gluteal skin and muscle necrosis should be kept in mind. (author)

[en] We devised a uniform compensation method to improve dose distribution using the field within a field technique in T-shaped irradiation for esophageal cancer. Isodose curves and dose volume histograms (DVH) of the esophagus in the treatment volume were examined in ten patients treated for esophageal cancers. For the DVH analysis, the prescription dose was 40 Gy to the center of the treatment volume, and the volume ratio of the esophagus receiving within ±5% of the prescription dose (38-42 Gy) was regarded as an index of dose homogeneity (V±5%). The peak dose in the conventional antero-posterior opposed fields irradiation existed at the clavicular level, and the 90% isodose curve crossing the esophagus almost corresponded to the top level of the aortic arch. When 40 Gy is irradiated, the maximum dose of the esophagus and V±5% were 45.55±0.55 Gy and 59.7±13.2% respectively. The dose distribution of the esophagus became relatively homogeneous when a 10% dose was added using the field within a field technique to the area under the bottom level of the aortic arch, and the maximum dose and V±5% were 42.53±0.94 Gy and 91.7±7.1% respectively. A 10% and more overdose area existed at the clavicular level in the conventional antero-posterior opposed fields irradiation. A relatively homogeneous dose distribution could be obtained using the field within a field technique. (author)

[en] We evaluated the usefulness of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) value in characterizing breast tumors. One hundred and two female subjects (112 lesions, 86 malignant, 26 benign) with histopathologically proven breast tumors underwent 1.5 T magnetic resonance (MR) imaging including DWI. We classified tumors as benign tumors, noninvasive ductal carcinoma (NIDCs), and invasive ductal carcinoma (IDCs) and evaluated the distribution patterns of high signal on DWI for each group. We also calculated the ADC values of the breast tumors to investigate the difference in mean ADC values between benign and malignant tumors; among benign tumors, NIDCs, and IDCs; and among the histological types. P<0.05 was considered statistically significant. The distribution patterns of high signal on DWI were inhomogeneous in a number of benign tumors and IDCs, but spotty or nodular in NIDCs. The mean ADC value of benign tumors was 1.31±0.36 x 10^-3 mm²/s; of malignant tumors, 0.84±0.31 x 10^-3 mm²/s; of IDCs, 0.82±0.33 x 10^-3 mm²/s; and of NIDCs, 0.89±0.20 x 10^-3 mm²/s. There were significant differences between benign and malignant tumors and among benign tumors, NIDCs, and IDCs. The mean ADC value of papillotubular types was 0.86±0.30 x 10^-3 mm²/s; of scirrhous types, 0.71±0.20 x 10^-3 mm²/s; and of solid-tubular types, 0.76±0.21 x 10^-3 mm²/s; that of papillotubular types was significantly higher than that of scirrhous types. The distribution patterns of high signal on DWI and ADC values were useful for characterizing the breast tumors. (author)

[en] Electron spin resonance (ESR) studies have been performed to investigate radicals induced in ethane hydrate irradiated by γ-rays at 77K. Two ESR spectra are observed and identified as the induced ethyl radical (g=2.0031±0.0005, A_αsub(perpendicular)=2.2±0.1mT, A_αsub(parallel)=2.5±0.1mT, A_β=2.7±0.1mT) and induced atomic hydrogen (g=2.0026±0.0005, A=50.5±0.1mT). From the results of ESR analysis and gas mass spectroscopy, it is concluded that the ethyl radical decays into butane by dimerization in the first-order reaction in the temperature region of 250-265K. The activation energy of the decay reaction is 73.1±6.3kJ/mol, which is near the dissociation enthalpy change of ethane hydrate to liquid water and gaseous ethane. This finding implies that ethane hydrate does not dissociate into ice but supercooled water in the present temperature region, similar to the dissociation of methane hydrate in our previous study. (author)

[en] The storage capacity of H₂ in the THF, THT, and furan hydrates was studied by p-V-T measurements. We confirmed that the storage and release processes of H₂ in all hydrates could be performed reversibly by pressure swing without destroying of hydrate cages. H₂ absorption in both THT and furan hydrates is much faster than THF hydrate in spite of same unit-cell structure. On the other hand, the storage amounts of H₂ are coincident in the all additive hydrates and would reach at about 1.0 mass% asymptotically.

[en] Highlights: ► Structural phase transition results in the heterogeneous azeotropic-like behaviour. ► HFC-134a molecules, in spite of an s-II former, occupy the large cages of s-I. ► Negative azeotropic-like behaviour becomes more remarkable at higher temperatures. - Abstract: Isothermal phase equilibria (pressure-composition relations in hydrate, gas, and aqueous phases) in the {difluoromethane (HFC-32) + 1,1,1,2-tetrafluoroethane (HFC-134a)} mixed-gas hydrate system were measured at the temperatures 274.15 K, 279.15 K, and 283.15 K. The heterogeneous azeotropic-like behaviour derived from the structural phase transition of (HFC-32 + HFC-134a) mixed-gas hydrates appears over the whole temperature range of the present study. In addition to the heterogeneous azeotropic-like behaviour, the isothermal phase equilibrium curves of the (HFC-32 + HFC-134a) mixed-gas hydrate system exhibit the negative homogeneous azeotropic-like behaviour at temperatures 279.15 K and 283.15 K. The negative azeotropic-like behaviour, which becomes more remarkable at higher temperatures, results in the lower equilibrium pressure of (HFC-32 + HFC-134a) mixed-gas hydrates than those of both simple HFC-32 and HFC-134a hydrates. Although the HFC-134a molecule forms the simple structure-II hydrate at the temperatures, the present findings reveal that HFC-134a molecules occupy a part of the large cages of the structure-I mixed-gas hydrate.

[en] Electron spin resonance (ESR) study on γ-irradiated synthetic ethylene hydrate was performed to investigate induced radicals and their thermal stability. ESR spectra of induced 3-butenyl radical (.CH₂C₂H₃=CH₂,g=2.0039±0.0005,A_α=2.2±0.1mTandA_β=3.0±0.1mT) and induced ethyl radical (.C₂H₅, g=2.0044±0.0005, A_α=2.2±0.1mT and A_β=2.7±0.1mT) were observed in irradiated ethylene hydrate. The decay of the 3-butenyl radicals was observed above 200 K with the activation energy of 51.9±4.4kJ/mol. The obvious decay of ethyl radicals starts above 240 K that is close to the dissociation temperature of ethylene hydrate at atmospheric pressure. The activation energy of the ethyl radical decay is estimated as 63.4±8.2kJ/mol and nearly equal to the enthalpy change of ethylene hydrate into liquid water and gaseous ethylene. It is suggested that the decay of ethyl radicals would be caused by the hydrate dissociation and that ethylene hydrate dissociates into water (supercooled) and ethylene at 240-265 K.

[en] Highlights: ► Isothermal three-phase equilibria for the heading system were measured. ► Two structural phase transitions of the mixed-gas hydrate are detected. ► Two homogeneous and one heterogeneous azeotropes are observed on an isotherm. - Abstract: Isothermal three-phase equilibria of gas, aqueous, and hydrate phases for the {xenon (Xe) + cyclopropane (c-C₃H₆)} mixed-gas hydrate system were measured at two different temperatures (279.15 and 289.15) K. The structural phase transitions from structure-I to structure-II and back to structure-I, depending on the mole fraction of guest mixtures, occur in the (Xe + c-C₃H₆) mixed-gas hydrate system. The isothermal pressure–composition relations have two local pressure minima. The most important characteristic in the (Xe + c-C₃H₆) mixed-gas hydrate system is that the equilibrium pressure–composition relations exhibit the complex phase behavior involving two structural phase transitions and two homogeneous negative azeotropes. One of two structural phase transitions exhibits the heterogeneous azeotropic-like behavior.

No abstract available