Measurements of acoustic particle velocity in a coaxial duct and its application to a traveling-wave thermoacoustic heat engine.

We present theoretical solutions, based on linear acoustic theory, for axial acoustic particle velocity in an annular region of a coaxial duct. The solutions are expressed in terms of two non-dimensional parameters h/δ(ν) and R; h and δ(ν), respectively, represent the half of the spacing between two concentric ducts and the characteristic length given by kinematic viscosity of the gas and angular frequency of acoustic oscillations, and R is the radius ratio of the ducts. The validity of the solutions was verified by direct measurements using a laser Doppler velocimeter. The present results are applied to measurements of the acoustic power distribution in a traveling wave thermoacoustic engine with a coaxial duct, which provides experimental evidence for acoustic power feedback in the coaxial duct.

Multicenter phase II study of weekly paclitaxel plus S-1 combination chemotherapy in patients with advanced gastric cancer.

BACKGROUND: A multicenter phase II study was conducted to evaluate the efficacy and safety of a combination regimen of weekly paclitaxel plus S-1 in patients with advanced gastric cancer. METHODS: Patients with previously untreated metastatic or recurrent gastric cancer received intravenous paclitaxel 50 mg/m(2) on days 1, 8, and 15, plus oral S-1 40 mg/m(2) b.i.d. on days 1 to 14 followed by 2 weeks off, in a 28-day cycle. RESULTS: A total of 54 patients were registered. All of them had measurable disease and were determined to be eligible for the present study. Two complete responses and 23 partial responses were confirmed, giving an overall response rate of 46.3%. At a final follow up of 3 years, the median progression-free survival and median overall survival were 6.0 and 14.3 months, respectively. Grade 3 neutropenia occurred in 14 patients, and grade 4 in 1 patient (total, 27.8%). The most serious nonhematological toxicity was diarrhea, where grade 3 occurred in 5 patients (9.3%). There were no treatment-related deaths. CONCLUSION: A combination of weekly paclitaxel plus S-1 was found to be well tolerated and effective in patients with advanced gastric cancer. Further investigation with comparative trials is needed for confirmation.

Phase I study of a combination of s-1 and weekly paclitaxel in patients with advanced or recurrent gastric cancer.

OBJECTIVE: A phase I study of weekly intravenous paclitaxel combined with a fixed dose of S-1, a dihydropyrimidine-dehydrogenase-inhibitory oral fluoropyrimidine, was conducted for patients with advanced or recurrent gastric cancer (ARGC). Endpoints of this study were to examine the toxicity profile OF this regimen and to determine the recommended dose (rd) of paclitaxel. METHODS: S-1 was fixed at a dose of 80 mg/m(2) per day and was administered for 2 weeks (days 1--14) followed by a 2-week rest. Two dose levels of paclitaxel (level 1: 60 mg/m(2), level 0: 50 mg/m(2)) were studied. Paclitaxel was infused over 1 h on days 1, 8, and 15. Plasma sampling was performed to characterize the pharmacokinetics and pharmacodynamics of paclitaxel in some patients. Fifteen patients were enrolled (6 patients in level 1, and 9 patients in level 0). Dose-limiting toxicities were defined as grade 4 hematological (including grade 3 febrile neutropenia) and grade 3 non-hematological (except anorexia, nausea, vomiting and depilation) toxicities. RESULTS: Three of 6 patients in level 1 developed grade 4 neutropenia or grade 3 febrile neutropenia, and 1 of them also showed grade 3 diarrhea, which settled the maximum-tolerated dose at this level. At level 0, 2 of 9 patients developed grade 4 neutropenia or grade 3 febrile neutropenia, and the RD of paclitaxel for this protocol was set at this level. Pharmacologic studies demonstrated the persistence of significant serum paclitaxel levels over 24 h after drug administration at both levels. Objective responses according to Response Evaluation Criteria in Solid Tumors were observed in 3 of 6 patients who had measurable disease. CONCLUSION: A combination of S-1 and weekly paclitaxel was feasible and well tolerated, and is suggested to produce a worthwhile response in ARGC. These results warrant further investigation, and a phase II study has already been started.